I found some old pictures at the back of my drawer which _____ memories of my childhood.
| A．called in | B．called up |
| C．called back | D．called off |
I’m into the video game, it’s hard to think of anything else. All my focus is on finishing 
the story line.
| A．Unless | B．Once | C．Whether | D．Although |
We live in a world that is changing fast, one changes come at what seems to be an ever-increasing pace.
| A．Unless | B．Once | C．Whether | D．Although |
Panda is one of remaining endangered animals in the world.
| A．The; The | B．A; a | C．The; a | D．不填；the |
I was told that there were about 50 foreign students ________ Chinese in the school, most ________ were from Germany.
A. studying, of whom B study, of them C. studying, of them D study, of whom
_________ by the teacher, Tom got into the classroom from the back door quietly.
| A．To avoid being seen | B．Avoiding seen | C．Avoid being seen | D．Avoided seeing |