The smog arrived in the Yangtze River Delta region on Nov．30，_________the air quality in 1 2 cities out of 25 was rated as severely polluted by Dec．1．
| A．where | B．when | C．which | D．what |
--- What do you think of the grammar book?
--- Oh, it really is ________ useful reference book, which is worth reading ________ second time.
| A．a; a | B．an; the | C．an; | D．the; the |
--Mary, remember to come and see us next time you’re in town.
---__________.
| A．Why? I’ll certainly do | B．Sounds nice |
| C．You’re welcome | D．Sure, I will |
——Shall I give you a ride as you live so far away?
——Thank you. ______.
| A．If you like | B．Of course you can |
| C．It couldn’t be better | D．It’s up to you |
Their youngest child is at the stage ___________she can say a few words but not full sentences.
| A．where | B．that | C．which | D．When |
It was Paul’s low test scores that_________ his chances of getting into a good school.
| A．recovered | B．protected |
| C．ruined | D．expressed |