. She _____ on this essay for twenty minutes but she has written only about a hundred words.
| A．will be working | B．worked | C．has been working | D．will have worked |
Please _______ when the train leaves.
A. look b. find out C. find D. look for
Our English teacher has __________ son.
| A．a 8-year-old | B．an 8-years-old | C．a 8-years-old | D．an 8-year-old |
Not only his parents but also his sister ________ the museum.
A. are going to B. is going to c. are going D. is going
This book is worth _____.
| A．to read it | B．reading it | C．reading | D．to read |
We should do ___ the teacher told us.
| A．because | B．like | C．as | D．since |