基坑在降低地下水位时,宜选用( )水泵。
A.大容量中高水头
B.小容量中低水头
C.小容量中高水头
D.大容量中低水头
参考答案:C
In 1776 the United States announced the Declaration of Independence to ______ from the British Empire and became an independent country.A. pull down B. break away C. get off D. drop off
重载输入流运算符>>必须使用的原型为( )。
A.istream& operator>>(istream&,<类名>&);
B.istream& operator>>(istream,<类名>);
C.istream operator>>(istream,<类名>&);
D.<类名>operator>>(istream&,<类名>&);