单项选择题

______ much is known about what occurs during sleep, the precise function of sleep and its different stages remains largely in the realm of assumption.

A．Because
B．For
C．Since
D．While
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单项选择题
You want to tell me, and I have no objection ______ it.
A．to hear
B．to hearing
C．heating
D．having heard
单项选择题
The composers soon began to write musical dramas about Bible stories ______ in church.
A．to perform
B．performing
C．to be performed
D．be performed
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