Theriverswillbecomedirtierandd

The rivers will become dirtier and dirtier _______ we take action to protect them.

A．since

B．if

C．until

D．Unless

登录免费查看答案和解析

相关试题

---I can’t find my scissors , can you help me buy______? ---Ok

A．the other one	B．other pair
C．another one	D．another pair

收藏答案/解析

--- Could you help me ______a shelf on the wall? ---No problem

A．put on	B．put in
C．put up	D．put off

收藏答案/解析

--- My son is two years old, but he can _________ draw. ---How clever!

A．teach himself to	B．teach to himself
C．learn by himself	D．study with himself

收藏答案/解析

--- __________ is the cost of the trip to Nanjing ? --- About forty yuan per person.
A. How B What C. How many D. How much

收藏答案/解析

---The students look very tired after the sports meeting.
---We’d better make them ____a rest in the classroom.

A．stop to have	B．to stop to have
C．stop having	D．to stop having

收藏答案/解析