计算：（2×10-6）2÷（10-4）3
式=4×10-12÷10-12=4×10-12×1012=4．
Throughout______ history, ______ English language is made up of the rules each group of people brought to Britain with them.
A．the, the
B．/,the
C．the,/
D．/,/
矿井备用通风机必须能在（）分钟内开动。
A．2
B．5
C．10
D．15
