（）是组成蛋白质的构件，（）是组成核酸的构件，（）是组成多糖的构件。
There are three bedrooms in the house,_____ is Mary’s.
A. the smallestof which
B. the smaller of which
C. the smallest of them
D. the smallest one
The Greens will move into the new house next Monday,_____ it will be completely finished.
A. by the time
B. by which time
C. by that time
D. by this time
Alice has a large collection of pictures,_____ was taken in London.
A. none of them
B. no one of which
C. all of which
D. none of which
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