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问题 选择题

下列关于酶的论述正确的是

①对底物有严格的选择性 ②酶在体内不能更新 ③温度越高酶的活性越大 ④酶制剂通常在低温下保存 ⑤酶能降低化学反应的活化能 ⑥酶只能在细胞内发挥催化作用 ⑦酶是活细胞产生的具有催化作用的有机物[ ]

A．①④⑤⑦

B．②④⑤⑦

C．②③④⑥

D．①②⑥⑦

答案

答案：A

完形填空
完形填空。
                                                                My School Day in London
      Tim Hunt is telling   1   Chinese classmates about his school day back home in London.
      "My school day in London is different   2   my school day here in China. School starts    3   nine o'clock.
I get up at 7:00   4   weekdays. I go to school by underground(地铁). It   5   about forty-five minutes. I have
lunch at school. Classes are over at 3:15.It is early, so I stay at school and play games   6   my friends. I am
in the basketball team. We practise(练)on Monday   7   Wednesday. We have a match   8   Friday afternoon.
     On Saturday morning I get up late. Then I   9   my parents tidy (弄整洁) the house and the garden. In the
evening I often go to a film or to club (俱乐部).On Sunday I have a good rest and of course, I do   10   !"
( )1. A. he       
( )2. A. from       
( )3. A. for       
( )4. A. for       
( )5. A. goes      
( )6. A. and       
( )7. A. to       
( )8. A. on       
( )9. A. want      
( )10. A. my homeworks		B. him       
B. in       
B. at       
B. of       
B. stands     
B. but      
B. and       
B. in       
B. help       
B. the homeworks		C. his       
C. of       
C. on     
C. on     
C. wants    
C. with    
C. at       
C. at     
C. ask       
C. my homework		D. their             
D. at                
D. in                
D. in               
D. takes         
D. about              
D. with             
D. for               
D. tell              
D. mine homework     
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判断题

透过玻璃窗晒太阳可以预防佝偻病。()
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