The post office is _____ to the bank. [ ]
A. closing
B. closed
C. close
D. to close
答案:C
下列计算中,正确的是[ ]
A.a2+2a2=3a4
B.2x3(﹣x2)=﹣2x5
C.(﹣2a2)3=﹣8a5
D.6x2m÷2xm=3x2
将标准状况下的V LHCl(气)溶于1000g水中,得到的盐酸密度为rg/cm3,则该盐酸的物质的量浓度为( )
A.
B.
C.
D.