He looks very sad because someone _______ his home and took away his computer last night. [ ]

A. broke out      

B. broke up      

C. broke off      

D. broke into

桩冠固位的叙述不正确的是( )

A．桩冠的固位力主要取决于冠桩与根管壁之间的摩擦力

B．桩冠的固位力主要取决于粘固剂产生的粘结力

C．冠桩越长，固位越好

D．桩直径大小与固位有关

E．与粘固剂无关