浇筑拱型结构，应自两边拱脚对称（）进行。浇筑圈梁、雨棚、阳台（）安全防护设施。
A.同时、应设置
B.同时、不要
C.随意、应设置
参考答案：A
Ladies and gentleman, please fasten your safety belts. The plane________. [ ]
A. is going to be taken
B. is taking off
C. has taken off
D. took off
简述EDI的具体实现方法
