已知一砖墙的隔声量为52dB,如果在其他条件不变的情况下将它的厚度减少一半,隔声量应为多少()
A.26dB
B.46dB
C.52dB
D.42dB
参考答案:B
—I’m sure Andrew will win the first prize in the final.
—I think so. He ___________ for it for months.
A.is preparing
B.was preparing
C.had been preparing
D.has been preparing