下列四种不同基因组成的人，基因组成正常且所生子女中不会出现单眼皮的是 [ ]
A．AD
B．AA
C．Aa
D．aa
答案：B
The students were ____ over the ____ problem, listening to the teacher with a ____ expression
on theirfaces. [ ]
A. puzzled; puzzling; puzzling
B. puzzled; puzzling; puzzled
C. puzzling; puzzling; puzzled
D. puzzling; puzzled; puzzling
建筑工程施工安全技术
在基坑开挖时，为保证邻近建筑物不受影响，应采取( )措施。
A．截水沟
B．放坡
C．排水
D．边坡支撑加固
