【单选题】沟槽开挖不正确的做法是( )
A.
机械挖槽时,应在设计槽底高程以上留不小于200mm的余量,待人工清理
B.
机械挖槽时,机械离沟槽伤口边缘应有一定的安全距离
C.
机械挖槽时,应由专人负责掌握挖槽断面尺寸和标高。
【单选题】In the atmosphere, carbon dioxide acts rather like a one-mirror--the glass in the roof of a green-house which allows the sun' s rays to enter but prevents the heat from escaping. According to a weathe...
A.
prevent the sun' s rays from reaching the earth' s surface
B.
mean a warming up in the Arctic
C.
account for great changes in the climate in the northern hemisphere
D.
raise the temperature of the earth' s surface
【单选题】manager acts like an adviser
【简答题】在Excel2007中,模板文件的扩展名为()。
【判断题】采用机械开挖沟槽时,应由专人负责掌握挖槽断面尺寸和标高。