坚持()原则,逐步将资源税扩展到占用各种自然生态空间
A、浪费资源付费
B、谁浪费资源、谁破坏生态谁付费
C、使用资源付费
D、谁污染环境、谁破坏生态谁付费
参考答案:C, D
B.0~2s内,电场力所做的功等于零
C.4s末带电粒子回到原出发点
D.2.5s~4s内,电场力的冲量等于零
It is no longer _________it was 20 years ago, ________it was so poorly equipped. [ ]
A. what; when
B. that; which
C. what; which
D. what; that