When the young man was shown the evidence, he _______ and told everything he had done to the police. 

A．broke up

B．broke away

C．broke off

D．broke down

填隙碎石施工备料时，填隙料的用量约为粗碎石质量的( )。

A．10%～20%
B．20%～30%
C．15%～30%
D．30%～40%