单项选择题

Water is an essential global resource and it is up to each of us to ______ it.

A．preserve
B．maintain
C．reserve
D．conserve
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单项选择题
By the end of next month we ______ the review on the research findings.
A．will finish
B．will be finishing
C．will have finished
D．have finished
单项选择题
Every member of the original cast was signed ______ her.
A．in addition to
B．except
C．except for
D．besides
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