水泥熟料中氧化镁的含量允许放宽到6.0％，需经过（）试验合格。
A.压蒸安定性
B.氧化镁的含量测定
C.凝结时间和安定性
D.安定性
参考答案：A
一般体温升高1℃，呼吸大约增加（）
A.4次／分
B.5次／分
C.6次／分
D.7次／分
E.8次／分
— Why does the lake smell terrible?
— Because large quantities of water ____ . [ ]
A. have polluted
B. is being polluted
C. has been polluted
D. have been polluted
