根据规定，计划单列市、经济特区的人民代表大会及其常务委员会在宪法、法律和行政法规允许

-Did you see who the driver was?

-No,so quickly _________that I couldn't get a good look at his face.                             

A. did the car speed by

B. the car sped by

C. does the car speed by

D. the car speeds by

读下图，完成小题。

小题1:上图所示景观中，主要由侵蚀作用形成的是      

A．a和b

B．b和c

C．c和d

D．b和d小题2:形成图中a图所示地貌景观，最主要的外力作用是      

A．流水溶蚀

B．流水侵蚀

C．风力堆积

D．流水堆积小题3:河流入海泥沙量的减少可能对河口三角洲带来的影响是

A．地下水位下降

B．河流流速减慢

C．淤积速度加快

D．出现侵蚀后退

、福岛核危机表明，人类需要重新审视核能的应用。仅有清洁是不够的，还必须是安全的，开发核能的同时，更要提高其可控性。这启示我们要坚持

A．量变和质变的统一

B．两点论与重点论的统一

C．个人与社会的统一

D．前进性与曲折性的统一

The committee _____ over the problem among themselves for two hours. [ ]

A has argued

B has been arguing

C have argued

D. have been arguing