关于Th细胞正确的是（）

A:需要同B细胞相互作用才能活化 B:Th细胞是均一的细胞亚群 C:需要识别抗原呈递细胞上同MHC－Ⅱ类分子结合的抗原 D:参与TI－Ag的应答 E:只辅助Tc细胞的免疫应答

衰变常数与班衰期TH之间的关系是（）

A:入=0.693Th B:入=0.693/Th C:入=Th/0.693 D:入=1.44Th E:以上都不对

理想气体在高温热源温度TH和低温热源温度TL之间的卡诺循环的热效率为（）

A:（TH-TL）/TH B:TH/（TH-TL） C:TL/（TH-TL） D:（TL-TH）/TH

理想气体在高温热源温度TH和低温热源温度TL之间的逆向卡诺循环的制冷系数为（）

A:（TH+TL）/TH B:TH/（TH-TL） C:TL/（TH-TL） D:（TL-TH）/TH

D The National Gallery Description: The National Gallery is the British national art museum built on the north side of Trafalgar Square in London. It houses a diverse collection of more than 2,300 examples of European art ranging from 13th-century religious paintings to more modern ones by Renoir and Van Gogh. The older collections of the gallery are reached through the main entrance while the more modern works in the East Wing are most easily reached from Trafalgar Square by a ground floor entrance Layout: The modern Sainsbury Wing on the western side of the building houses 13th- to 15th-century paintings, and artists include Duccio, Uccello, Van Eyck, Lippi, Mantegna, Botticelli and Memling. The main West Wing houses 16th-century paintings, and artists include Leonardo da Vinci, Cranach, Michelangelo, Raphael, Bruegel, Bronzino, Titan and Veronese. The North Wing houses 17th-century paintings, and artists include Caravaggio, Rubens, Poussin, Van Dyck, Velazquez, Claude and Vermeer. The East Wing houses 18th- to early 20th-century paintings, and artists include Canaletto, Goya, Turner, Constable, Renoir and Van Gogh. Opening Hours: The Gallery is open every day from 10am to 6pm (Fridays 10am to 9pm) and is free, but charges apply to some special exhibitions. Getting There: Nearest underground stations: Charing Cross (2-minute walk), Leicester Square (3-minute walk), Embankment (7-minute walk), and Piccadilly Circus (8-minute walk). In which century’s collection can you see religious paintings

A:The 13th. B:The 17th. C:The 18th. D:The 20th.

[th] ______

[+Cons, +Alveolar, -Voiced, +Spread]

Even though ulcers appear to run in families, lifestyle plays more of role than genetic factors in causing the illness, according to a report in the April 13th Journal of Internal Medicine. In particular, smoking and stress in men and the regular use of pain releasing medicines in women were linked with an increased risk of developing an ulcer.
Overall, 61% of ulcer risk appears to be due to environmental actors, such as smoking, and the remaining 39% is due to genes according to Dr. Ismo Raiha of the University of Turky and colleagues at the University of Helsinki, Finland. Some researchers had suggested that families may spread Helicobacteria pylori, the bacteria that can cause ulcers. However, the new study suggests this is unlikely, according to the report.
Raiha and colleagues studied data from more than 13,000 pairs of twins "to examine the roles of genetic and environmental factors in the origin of peptic ulcer disease," they explain. Both twins were more likely to develop an ulcer if the pair were genetically the. same as compared with a pair of fraternal twins, suggesting that there must be some genetic susceptibility to ulcer development.
However, the risk was no greater in twins living together compared with twins living apart, suggesting that shared exposure to H. pylori was not to blame. "Environmental effects were not due to factors shared by family members, and they were related to smoking and stress in men and the use of analgesics in women," the authors wrote. "The minor effects of shared environment to disease liability do not support the concept that the grouping of risk factors, such as H. pylori infection, would explain the genetic factor of peptic ulcer disease," they concluded.
What does "environmental effects" in the fourth paragraph refer to

A:A clean environment with no smoke and dust surrounding the living area. B:Smoking and stress in men and use of pain-killing medicine in Women. C:Factors shared by family members such as genes and the food they eat. D:Shared exposure toH. pylori infection in the unclean environment.