单项选择题

Nowhere in nature is aluminum found free, owing to its always ______ with other elements, most commonly with oxygen.

A. being combined
B. having combined
C. to combine
D. combined
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The police carried out a(n) ______ search for the missing boy.
A. complete
B. entire
C. thorough
D. whole
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If the weather had been more favorable, the crops ______ still better.
A. will be growing
B. are growing
C. would have been growing
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