答案:D
花岗石中的石英在753℃时,体积发生剧烈膨胀,使花岗石爆裂,甚至松散。所以花岗石怕受火烤,施工和生活过程中应引起注意。( )
The students want to know ____ 1,600 words in a month.
A.how can they remember
B.how they can remember
C.when could they remember
D.when they could remember