人类的许多疾病如艾滋病,流感,病毒性肝炎都是由病毒引起的。

以肠道病毒71型为主要病原体的疾病是

A:急性荨麻疹 B:手足口病 C:小儿秋季腹泻 D:猩红热 E:心包膜炎

小舞蹈病

A:纹状体中多巴胺含量减少，乙酰胆碱作用相对增强 B:纹状体中乙酰胆碱含量减少，多巴胺作用相对增强 C:由于铜代谢障碍造成中枢神经系统病变 D:纹状体中多巴胺含量减少，乙酰胆碱含量增加 E:纹状体中乙酰胆碱含量减少，多巴胺含量减少

慢性进行性舞蹈病

A:纹状体中多巴胺含量减少，乙酰胆碱作用相对增强 B:纹状体中乙酰胆碱含量减少，多巴胺作用相对增强 C:由于铜代谢障碍造成中枢神经系统病变 D:纹状体中多巴胺含量减少，乙酰胆碱含量增加 E:纹状体中乙酰胆碱含量减少，多巴胺含量减少

血友病

A:紫癜伴关节腔出血 B:紫癜伴休克或其他部位广泛严重出血 C:紫癜伴黄疸 D:紫癜伴发热 E:紫癜伴严重贫血

肝脏疾病

A:紫癜伴关节腔出血 B:紫癜伴休克或其他部位广泛严重出血 C:紫癜伴黄疸 D:紫癜伴发热 E:紫癜伴严重贫血

人类的许多疾病如艾滋病、流感、病毒性肝炎都是由病毒引起的。

以肠道病毒71型为主要病原体的疾病是

A:急性荨麻疹 B:手足口病 C:小儿秋季腹泻 D:猩红热 E:心包膜炎

某4月龄鸡群发病，病鸡消瘦，昏迷，翅膀下垂，有的两腿前后伸展呈"大劈叉"姿势。剖检见单侧坐骨神经丛和臂神经丛肿大增粗，部分病鸡的肝脏和肾脏出现肿瘤。

此病最可能是

A:禽白血病 B:马立克氏病 C:新城疫 D:传染性法氏囊病 E:鸡病毒性关节炎

营养性维生素D缺乏性佝偻病(rickets0fvitaminDdeficiency)

是由于儿童体内维生素D不足使钙、磷代谢紊乱，产生的一种以骨骼病变为特征的全身慢性营养性疾病。

Vitamins are important to our health．Difierent vitamins are found in difierent foods．grains．vegetables and fruits，fish and meat，eggs and milk products．So which foods should be eaten to get enough of the vitamins our bodies needLet us look at some important vitamins for the answer．
Vitamin A helps prevent skin and other tissues from becoming dry．People who do not get enough Vitamin A cannot see well in darkness．They may develop a condition that dries the eyes．This can result in infections and lead to blindness．Vitamin A is found in fish liver oil．It is also in the yellow part of eggs．Sweet potatoes．carrots and other darkly colored fruits and vegetables contain substances that the body can change into Vitamin A．
Vitamin B is also called thiamine(硫胶)．Thiamine changes starchy foods jnto energy．It also helps the heart and nervous system work smoothly．Without it．we would be weak and would not grow．We also might develop beriberi(脚气病)．Thiamine is found not iust in whole grains like brown rice．but also jn other foods．These include beans and peas．nuts．and meat and fish．
Vitamin C is needed for strong bones and teeth．and for healthy blood passages．It also helps wounds heal quickly．The body stores little Vitamin C．So we must get it every day in foods such as citrus fruits，tomatoes and uncooked cabbage．
Vitamin D increases levels of the element calcium(铲)in the blood．Calcium is needed for nerve and muscle cells to work normally．It is also needed to build strong bones．VitaminD prevents the children’s bone disease rickets(佝偻痫)．Ultraviolet light from the sun changes a substance in the skin into vitamin D Fish liver oil also contains vitamin D．In some countries．milk producers add vitamin D to milk so children will get enough．
Vitamin K is needed for healthy blood．It thickens the blood around a cut to stop bleeding．Bacteria in the intestines f肠道)normally produce vitamin K．It can also be found in pork products．1iver and in vegetables like cabbage．kale and spinach．
Lack of Vitamin A will lead to ______．

A:night blindness B:heart disease C:beriberi D:rickets

Vitamin D helps bones and muscles grow strong and healthy. Low levels of vitamin D can lead to problems like rickets and osteoporosis. Rickets is a deformity mainly found in children. Osteoporosis is the thinning of bone, a common problem as people, especially women, get older. Studies in recent years have suggested that vitamin D may also have other uses. Studies have shown that low levels of D may increase the risk of heart attacks in men and deaths from some cancers. Other studies have shown that people with rheumatic diseases often have low levels of D.
The easiest way to get vitamin D is from sunlight. The ultraviolet rays react with skin cells to produce the vitamin. But many people worry about skin cancer and skin damage from the sun. Also, darker skinned people produce less vitamin D than lighter skinned people. Production also decreases in older people and those living in northern areas that get less sunlight.
Not many foods naturally contain vitamin D. Foods with high levels include oily fish such as salmon, tuna and mackerel, and fish liver oils. Small amounts of D are found in beef liver, cheese and egg yolks. Most of the D in the American diet comes from foods like milk with the vitamin added.
These days, more doctors are testing for vitamin D levels in their patients. But as research continues, some experts worry that if people take too much D, it might act as a poison. Also, skin doctors warn people to be careful with sun exposure.
How much vitamin D does a healthy person need Nutrition experts who advise the American government set the current recommendations in nineteen ninety -seven. The daily amount is two hundred international units from birth through age fifty. Then it rises to four hundred I. U. s through age seventy, and six hundred for those seventy--one and older. But some groups say these amounts are not high enough.
Low levels of Vitamin D can lead to problems except

A:rickets and osteoporosis. B:heart attacks. C:rheumatic diseases. D:skin damag