眼的折光系统中，折射能力最大的界面是

A.at

B.不填

C.on

D.with

I have spent a lot more time studying English than Li Ping ______.

A．have

B．has

C．does

D．did

A.at

B./

C.on

The author concludes in the last paragraph that ______.

A．governments have spent lots of time in solving the ageing problem

B．population ageing is a hard problem, but it needs to be solved urgently

C．people are too busy to solve the population ageing problem

D．much time and effort will be lost in solving the ageing problem

Now that I'm only working part time，I have a hard time making _____ meet .

A.hands

B.arms

C.days

D.ends

The author concludes in the last paragraph that ______.

A．governments have spent lots of time in solving the ageing problem

B．population ageing is a hard problem, but it needs to be solved urgently

C．people are too busy to solve the population ageing problem

D．much time and effort will be lost in solving the ageing problem

The author concludes in the last paragraph that ________.

A. governments have spent lots of time in solving the ageing problem B. population ageing is a hard problem, but it needs to be solved urgently C. people are too busy to solve the population ageing problem D. much time and effort will be lost in solving the ageing problem

I have seen people (spend)______ too much time on the problem and too little time on the solution.

By the time you arrive, I ______ working for two hours

A. will be

B. can

C. will have been

D. have been