酶的催化机制完全可以用酶与底物的“锁钥学说”阐明。()
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听力原文：Hello, this is Mike. Can I speak to Mr. Smith？
(2)
A. Mr. Smith is happy today.
B. Sorry, Mr. Smith is not in.
C. lie's glad to see you.
D. Tell me your number, please.
People will appreciate______if an appointment is cancelled.
A. you to call them
B. that you are calling them
C. that you would call them
D. your calling them
______ in the queue for half an hour, Tom suddenly realized that he had left his wallet at
A. To wait
B. Waiting
C. Having waited
D. To have waited
Which of the following statement is NOT mentioned in the passage？
A. Modem cities offer better schools, more chances of work.
B. The air is polluted,
C. The people lose connection with nature.
D. The people can not enjoy sunshine and fresh air.
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