Sometimes in summer, when ______ sun is rising, you can still see ______ clear moon hanging in the sky.

A．the, the

B．a, the

C．the, a

D．a, a

物体所含物质的______叫做质量．地球的质量是6.0×10²⁴Kg，相当于______t．一枚大头针的质量约 8.0×10^-5 Kg，合______mg．