Five and a half years into his presidency, George Bush finally vetoed a bill this week. Oddly enough, it was one that most Americans support: it would have expanded foderal funding for embryonic stem-cell research. The House and Senate had both passed the bill by wide, but not veto-proof margins, so Mr. Bush’s word is final, at least until after the mid-term elections in November.
Stem cells are cells that have not yet decided what they want to be when they grow up. That is, they can become blood cells, brain cells, or pretty much any other type of cell. Their versatility makes them extremely useful for medical research. The ethical snag is that the best stem cells are harvested from human embryos, killing them. For the most ardent pro-lifers, including Mr. Bush and many of his core supporters, that is murder. Proponents of embryonic stem-cell research point out that hordes of embryos are created during fertility treatment, and the vast majority of these are either frozen indefinitely or destroyed. Is it really wrong to use them for potentially life-saving research Yes, said Mr. Bush on July 19th, flanked by some families who had "adopted" other people’s frozen embryos and used them to have children of their own.
Mr. Bush’s veto does not kill stem-cell research. Scientists who spurn federal cash may do as they please. The government still pays for research on stem cells taken from adults, a process that does not kill the donor. And a decision by Mr. Bush in 2001 allows federally-funded scientists to experiment on the few dozen embryonic stem-cell "lines" that already existed then, which can be propagated in a laboratory.
Nonetheless, scientists are furious with Mr. Bush. Federal funding would surely push them faster towards those elusive cures. Research based on adult stem cells may be promising, but not nearly as promising as that based on embryonic ones. There are worries that those few dozen embryonic stem-cell lines represent too narrow a gene pool, and that they cannot be endlessly extended without damaging them. Other countries, such as Britain and China, are enthusiastically experimenting on embryonic stem cells. But the world’s most innovative nation is hanging back.
Scientists can go on the stem cell research because ______.

A:scientists spurn the government and Mr Bush’s veto. B:other countriesare enthusiastically experimenting on embryonic stem cells. C:Mr. Bush’s veto does not stop stem cell research completely. D:all the scientists in America are furious with Mr. Bush.

Five and a half years into his presidency, George Bush finally vetoed a bill this week. Oddly enough, it was one that most Americans support: it would have expanded foderal funding for embryonic stem-cell research. The House and Senate had both passed the bill by wide, but not veto-proof margins, so Mr. Bush’s word is final, at least until after the mid-term elections in November.
Stem cells are cells that have not yet decided what they want to be when they grow up. That is, they can become blood cells, brain cells, or pretty much any other type of cell. Their versatility makes them extremely useful for medical research. The ethical snag is that the best stem cells are harvested from human embryos, killing them. For the most ardent pro-lifers, including Mr. Bush and many of his core supporters, that is murder. Proponents of embryonic stem-cell research point out that hordes of embryos are created during fertility treatment, and the vast majority of these are either frozen indefinitely or destroyed. Is it really wrong to use them for potentially life-saving research Yes, said Mr. Bush on July 19th, flanked by some families who had "adopted" other people’s frozen embryos and used them to have children of their own.
Mr. Bush’s veto does not kill stem-cell research. Scientists who spurn federal cash may do as they please. The government still pays for research on stem cells taken from adults, a process that does not kill the donor. And a decision by Mr. Bush in 2001 allows federally-funded scientists to experiment on the few dozen embryonic stem-cell "lines" that already existed then, which can be propagated in a laboratory.
Nonetheless, scientists are furious with Mr. Bush. Federal funding would surely push them faster towards those elusive cures. Research based on adult stem cells may be promising, but not nearly as promising as that based on embryonic ones. There are worries that those few dozen embryonic stem-cell lines represent too narrow a gene pool, and that they cannot be endlessly extended without damaging them. Other countries, such as Britain and China, are enthusiastically experimenting on embryonic stem cells. But the world’s most innovative nation is hanging back.
It can be inferred from the last paragraph that ______.

A:the House and Senate are furious with Mr. Bush on behalf of the scientists. B:research based on adult stem cells must be more promising than embryonic ones. C:many countries, except America, are keen on experimenting embryonic stem cells. D:the UK is enthusiastic about experimenting on adult stem cells.

Five and a half years into his presidency, George Bush finally vetoed a bill this week. Oddly enough, it was one that most Americans support: it would have expanded foderal funding for embryonic stem-cell research. The House and Senate had both passed the bill by wide, but not veto-proof margins, so Mr. Bush’s word is final, at least until after the mid-term elections in November.
Stem cells are cells that have not yet decided what they want to be when they grow up. That is, they can become blood cells, brain cells, or pretty much any other type of cell. Their versatility makes them extremely useful for medical research. The ethical snag is that the best stem cells are harvested from human embryos, killing them. For the most ardent pro-lifers, including Mr. Bush and many of his core supporters, that is murder. Proponents of embryonic stem-cell research point out that hordes of embryos are created during fertility treatment, and the vast majority of these are either frozen indefinitely or destroyed. Is it really wrong to use them for potentially life-saving research Yes, said Mr. Bush on July 19th, flanked by some families who had "adopted" other people’s frozen embryos and used them to have children of their own.
Mr. Bush’s veto does not kill stem-cell research. Scientists who spurn federal cash may do as they please. The government still pays for research on stem cells taken from adults, a process that does not kill the donor. And a decision by Mr. Bush in 2001 allows federally-funded scientists to experiment on the few dozen embryonic stem-cell "lines" that already existed then, which can be propagated in a laboratory.
Nonetheless, scientists are furious with Mr. Bush. Federal funding would surely push them faster towards those elusive cures. Research based on adult stem cells may be promising, but not nearly as promising as that based on embryonic ones. There are worries that those few dozen embryonic stem-cell lines represent too narrow a gene pool, and that they cannot be endlessly extended without damaging them. Other countries, such as Britain and China, are enthusiastically experimenting on embryonic stem cells. But the world’s most innovative nation is hanging back.

It can be inferred from the last paragraph that（）

A:the House and Senate are furious with Mr. Bush on behalf of the scientists. B:research based on adult stem cells must be more promising than embryonic ones. C:many countries, except America, are keen on experimenting embryonic stem cells. D:the UK is enthusiastic about experimenting on adult stem cells.

Stem cell

stem

Stem is any morpheme or combination of morphemes to which an inflectional affix can be added，e.g. ，friend-infriends，friendship-infriendships．

The banana "tree" is actually not a real tree. This is because there is no wood in the stem (树 干) rising above the ground. The stem is made up of leaves growing very close together, one inside the other. The leaves spread out at the top of the stem and rise in the air.
Banana plants need a lot of care and attention. They must be provided with water if the normal rainfall doesn’t supply enough. The area around the plants must be kept free of weeds (杂草) and grass.
About nine or ten months after planting, a flower appears on the banana plant. This flower is at the end of a long stalk (茎), which grows from the base up through the center of the stem arid turns downward when it comes out from the top. Small bananas form on this flower stalk as it grows downward. Bananas really grow upside down. As the small bananas form on the stalk, they, point downward, but as they grow they turn and point upward.
Bananas are harvested while they are still green. Even when they are to be eaten where they are grown, they are not allowed to ripen on the plant. A banana that turns yellow on the plant loses its taste.,

The first paragraph in the text mainly discusses （　）

A:why the stem of the tree is wood B:how the banana grows on the stem C:why the banana tree is not a tree D:how the leaves grow out of the stem

The banana "tree" is actually not a real tree. This is because there is no wood in the stem (树 干) rising above the ground. The stem is made up of leaves growing very close together, one inside the other. The leaves spread out at the top of the stem and rise in the air.
Banana plants need a lot of care and attention. They must be provided with water if the normal rainfall doesn’t supply enough. The area around the plants must be kept free of weeds (杂草) and grass.
About nine or ten months after planting, a flower appears on the banana plant. This flower is at the end of a long stalk (茎), which grows from the base up through the center of the stem arid turns downward when it comes out from the top. Small bananas form on this flower stalk as it grows downward. Bananas really grow upside down. As the small bananas form on the stalk, they, point downward, but as they grow they turn and point upward.
Bananas are harvested while they are still green. Even when they are to be eaten where they are grown, they are not allowed to ripen on the plant. A banana that turns yellow on the plant loses its taste.,

The underlined word "it" in the third paragraph refers to （　）

A:the leaf B:the stalk C:the stem D:the plant

The banana "tree" is actually not a real tree. This is because there is no wood in the stem (树 干) rising above the ground. The stem is made up of leaves growing very close together, one inside the other. The leaves spread out at the top of the stem and rise in the air.
Banana plants need a lot of care and attention. They must be provided with water if the normal rainfall doesn’t supply enough. The area around the plants must be kept free of weeds (杂草) and grass.
About nine or ten months after planting, a flower appears on the banana plant. This flower is at the end of a long stalk (茎), which grows from the base up through the center of the stem arid turns downward when it comes out from the top. Small bananas form on this flower stalk as it grows downward. Bananas really grow upside down. As the small bananas form on the stalk, they, point downward, but as they grow they turn and point upward.
Bananas are harvested while they are still green. Even when they are to be eaten where they are grown, they are not allowed to ripen on the plant. A banana that turns yellow on the plant loses its taste.,

According to the text, where do bananas actually grow（　）

A:On the stem. B:On the leaves. C:On the flower stalk. D:On the base of the stem.