基坑内明排水应设置排水沟及集水井,排水沟纵坡宜控制在( )。
A.1‰~2‰ B.1‰~3‰ C.2‰~3‰ D.2‰~4‰
参考答案:A
As I grew up in a small town at the foot of a mountain, the visit to the village _____ scenes of my childhood. [ ]
A. called up
B. called for
C. called on
D. called in
患儿突然发热、咽痛、"杨梅舌",病后第3天,耳后颈部出现皮疹,然后发展为全身弥漫性鲜红皮疹,疹退后有皮屑。咽拭子培养的结果亦支持此病是猩红热。猩红热皮疹产生的原因是()
A.链球菌溶血素的毒性作用
B.链球菌致热外毒素的毒性作用
C.透明质酸酶的扩散作用
D.链球菌DNA酶的扩散作用
E.链球菌链激酶的扩散作用