It’s the test system rather than the teachers ________to blame for the students’ heavy burden nowadays.

A．who are

B．whom is

C．that is

D．that are

某天体的质量约为地球的9倍，半径约为地球的一半，若从地球上高h处平抛一物体，射程为L，则在该天体上，从同样高处以同样速度平抛同一物体，其射程为 (      )

A．L/6

B．L/4

C．3L/2

D．6L