下列各句中，加线的成语使用不恰当的一项是(　　)

_ ____, the boys were shouting and singing.

Seen from space, the earth looks like a blue ball, with ______ 75% of its surface covered with water[ ]

________ do you stay at home at weekends— Ten hours.

It’s said to be a case of murder_______ the childrenwere used by adults