如果两个部门要素密度完全相同，要素禀赋差异还会引发国际贸易吗？

In fact he knows this place very well, for he ________ there three times.

A．has been

B．has been to

C．has gone

D．has gone to

—Tom played basketball all the morning.

--Yeah, he is a(n)_________boy. He hardly ever feels tired.

A．outgoing

B．creative

C．energetic

D．confident

欲除去NaNO₃溶液中混有少量的CuSO₄杂质，应加入一种适量的______溶液，然后再进行______操作．

保证期间，债权人依法将主债权转让给第三人的，保证人在( )的范围内继续担保保证责任。

A．原保证担保

B．主合同债权

C．新合同约定

D．债权的全部

宗教信仰属于公共营养师需要收集的社区人群基础资料。