pH<3时会引起蛋白质的变性,大多数生物将不能存活。()
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一般说,食物链可以多于五个营养级。()
A. 正确
B. 错误
The bike is ______.
A. Chinese
B. English
C. Jim's sister's
Who is ten years old? ______.
A. Mike
B. Lucy
C. Jim
听力原文:W: I'm sorry for that.
(13)
A. I'm afraid not.
B. That's all right.
C. Thank you very much.