---Please come here again.
-----I will surely ____ you when I come to your city someday.
| A．drop in at |
| B．drop in |
| C．drop on |
| D．drop in on |
Over 20% of the students at that school _____ the habit of smoking, which is beyond imagination.
| A．is | B．are | C．has | D．have |
I will never forget the day _____ we spend together.
| A．when | B．on that | C．which | D．while |
----Where shall we go first?
---- According to ____ schedule of the journey, firstly, we’ll visit ____ temple, the guide told us.
| A．a; a | B．the; a |
| C．a; the | D．the; the |
As a student, you should try to ______ being late for your class.
| A．avoid | B．refuse | C．prevent | D．punish |
This is ______ difficult problem that few students can work it out.
| A．so | B．so a | C．such | D．such a |