降低铆螺钢生产时的终轧温度，能使实际晶粒增大，会使其机械性能（）。
A、提高
B、降低
C、不变
D、不确定
参考答案：B
.When we reached the station, the train had still not arrived; so we ______.
a. needed not to hurry b. needn’t have hurried
c. need not to have hurried d. didn’t need to hurry
CYP3A主要存在于（）
A.心
B.肝
C.小肠
D.肾
E.脑
