A．worryB．worriedC．failD．failed
A. worry
B. worried
C. fail
D. failed
查看答案
Which of the following best reveals the main idea of the passage？
A. Surprising discoveries of new species are commonplace.
B. The mystery of the deep sea and the soil remains to be uncovered.
C. Knowledge of global species diversity is still limited.
D. Estimates of global species diversity vary among scientists.
What is e-mail？
A live conversation with an expert.
B. A means of communication.
C. A long-distance call service.
D. A mail delivery system.
A．withB．byC．withoutD．from
A. with
B. by
C. without
D. from
A．askB．doubtC．careD．wonder
A. ask
B. doubt
C. care
D. wonder
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