1.   The zipper is a good__________ for iks human beings.

2.   Dr. Naismith________ a new game called basketball.

3.   The number of Chinese students in Canada has 

4.   The class is__________ into five groups.

5.   It is_________  that he is an honest student.

5. We should__________ a new plan for our vacation.

A. come up           B. come up with

C. thought of         D. thought up with

4.  —Do you know when the abacus(算盘)__________ ？

―In the sixth century.

A. is invented        B. are invented

C. was invented       D. were invented

3.    I didn't understand the drawing _____________   I read the description of it.

A. because of         B. until

C. because           D. if

2. —Who designed this game?
—It________ by Tom in 2013.

A. is designed       B. designs

C. was designed      D. designed

1. The  number  of  the  teachers   in  our school__________450 now.

A. are      B. is      C. were        D. was

3.   很难判定是谁先想出的这个主意。

It's hard to tell who_________  __________  __________ the idea first.

2.   很难判定某些发明的发明者是谁。

________  _________  _______ __________ on the inventor of certain inventions.

1.   这支特殊的钢笔是由刘杰发明的。

The special pen _____ ________ by Liu Jie.

1.    There is no__________  that the computer is a good invention.

2.    Who is the_________ of the special pen?

3.    It has three colors and is____________ for drawing.

4.    You can get a lot of information if you search the________ .