肠扭转可引起肠壁（） A.贫血性梗死 B.干性坏疽 C.气性坏疽 D.出血性梗死 E

183580300 读作______．

对乙公司以50万元价格将该批机床出卖给丙公司的行为是否合法，效力如何

American researchers say drinking tea may help strengthen the body’s defense system against infection（感染）．Doctors at Brigham and Women’s Hospital in Boston，Massachusetts，did the study．The team studied a chemical found in black，green，oolong and pekoe tea This chemical is an amino acid（氨基酸）called L-theanine．The scientists say it may increase the strength of Gamma delta T cells，which are part of the body’s defenses．

First，the researchers mixed some of these cells with antigens（抗原）found in the amino acid Antigens help the body react to infection．Then the scientists added some bacteria（细菌）．

Within twenty-four hours，the cells produced a lot of interferon，a substance that fights infection Cells not mixed with the antigens did not produce interferon．

In the second part of the study，eleven people drank five to six cups of black tea every day．Ten other people drank the same amount of instant coffee．That is dried coffee mixed with hot water．

Two weeks later，and again two weeks after that，the researchers tested the blood of all twenty-one people．They also looked at what happened when they added bacteria to the blood cells．They found that the tea drinkers produced five times more interferon after they started drinking tea The coffee drinkers did not produce interferon．

Doctor Jack Bukowski led the study He says the antigens added to the Gamma delta T cells were responsible for the increased reaction to the bacteria．He says the study also showed that the cells were able to remember the bacteria and fight them again the next time．

Earlier research already has found that tea can help prevent heart disease and cancer Doctor Bukowski says the new study must be repeated with more people．If the findings prove to be true，he says，then tea drinking might also help protect against bacterial infections．He says the amino acid L-theanine could be removed from tea and used as a drug to strengthen the body’s defenses．

73．We may know from the text that     can be found in different kinds of tea．

A．Gamma delta T cells                               B．L-theanine

C．interferon                                       D．bacteria

74．Tea may help strengthen the body’s defense system because it helps    ．

A．the body to produce more interferon

B．the body to produce more Gamma delta T cells

C．to add some bacteria to the blood cells

D．to mix antigens with some of the cells in the body

75．According to Dr Bukowski，    ．

A．the findings of the study have already proved to be true

B．he bas taken some amino acid L-theanine from tea and made a drug with it

C．further study is needed to prove the findings true

D．he is not sure whether tea can help prevent heart disease and cancer

胰腺的下方与胰腺平行的结构是（）

A.腹腔动脉

B.脾静脉

C.肾静脉

D.门静脉

( )内驱力将学业成就看做是赢得地位和自尊的根源。

A．学习
B．认知
C．自我提高
D．附属