—Where is Joy?
—He _____ to the library[ ]
A. went
B. has gone
C. has been
答案：B
仅可以在合格机构投资者范围内交易的ADR是( )。
A．一级有担保ADR
B．二级有担保ADR
C．三级有担保ADR
D．144A规则下的私募ADR
什么是海蚀作用，海蚀地貌有哪些？
