The bell ____ the end of the period rang and we had to stop our discussion
| A．indicating | B．indicated |
| C．to be indicated | D．being indicated |
I can well remember that there was a time _____I played sports with my close friends in junior school.
| A．what | B．which | C．that | D．when |
While _________the topic of music in class, all the students show great interest in it.
| A．discussed | B．discuss |
| C．discussing | D．are discussing |
Please wait a minute, honey! I _______ my work.
| A．have finished | B．am finishing |
| C．finished | D．finish |
Great changes _________ in many fields since China was open to the whole world.
| A．have taken place | B．took place |
| C．have been taken place | D．were taking place |
_____you’ve made a promise, you are expected to carry it out.
| A．While | B．Unless |
| C．Once | D．Though |