井筒内运送爆破材料必须事先通知（）和（）。
参考答案：绞车司机、 井上、下把钩工 。
By the end of last year, another new gymnasium ________in Beijing. [ ]
A. would be completed
B. was being completed
C. has been completed
D. had been completed
简述《中华民国宪法》(1947年)的结构特点、主要内容及其实质。
