The air pollution is a serious in our country． Our government is trying to solve it．（ ）
| A． |
choice |
B． |
program |
C． |
problem |
D． |
opinion |
We talked about _____ new words．（ ）
A．learnB．learnedC．learningD．to learn
﹣I left my pen at home．Can you lend me one？（ ）
A．Yes，of courseB．Thank you
C．Yes，just a littleD．Hold on，please
It old the teacher _____ I had seen．（ ）
A．whatB．whichC．whereD．that
﹣Excuse me，is this the right way to the Children's Palace？
﹣Sorry，I'm not sure．But it _____ be．（ ）
A．mustn'tB．mightC．can'tD．must
We ______ have a picnic together with our teachers next Thursday．（ ）
A．are goingB．are going to
C．will goingD．may going to