人们进入劳动年龄段以后,通常情况下,人有()时间是在作业现场度过的,因此改善劳动条件与劳动环境是十分重要的。
A.1/2
B.1/3
C.1/4
参考答案:B
— Have you ever come here before?
— No. It is my first time that I to this city.
A.have been
B.had been
C.came
D.come
外部性