台湾左镇人化石是在台湾何地发现的？（） A.台东 B.台北 C.台南 D.高

It's wonderful to hike with Dad and I have felt _____ with him. [ ]

A. to protected

B. protected

C. protecting

D. to be protected

下面的原子或原子团不属于官能团的是[ ]

A．NO₃^-

B．-Cl

C．-OH

D．

This isn't _____ pencil case. I left _____ at home. [ ]

A. my, mine

B. me, my

C. I, my

D. my, myself

我国现有环境管理制度有那些？

十进制数90转换成二进制数是( )。

A．1011010

B．1101010

C．1011110

D．1011100