—I want to return the book to Jack, but I can't find him.

—He _____ the library. You can find him there. [ ]

A. has been to

B. has gone to

C. has left

D. went to

关于督促程序，下列说法正确的有______

A．因为公告送达是一种推定送达，难以保障债务人异议权的实现，所以督促程序中不适用公告送达的方式

B．督促程序是一种简便、快捷的实现债权的非讼程序

C．在人民法院发出支付令前，债权人可以撤回申请，是否准许，由人民法院审查决定

D．在督促程序终结前，债务人可以请求撤回异议，人民法院应当准许

E．债务人提出异议的形式可以是书面的，也可以是口头的