2 . 下列各句均有一处错误，请指出并加以改正。
1. Kate is my the best friend.__________
2. This book is more cheaper than that one.__________
3. My mother is tireder than I.__________
4. This question is importanter than that one.__________
5. Tom is younger of the two boys.__________
6. Kate writes more careful than Tom.__________
7. Who is older，Kate，Rose or Lily? __________
8. The Changjiang River is the third long river in the world.__________
9. Li Lei is taller than any other girl in his class.__________
10. Tom worked more hardly than Bill.__________

3 . —Have you finished all your exercises?
—Yes, ________ is left. As a matter of fact, they are as easy as ABC.

A．nothing

B．not one

C．none

D．neither

4 . The CDs are on sale! Buy one and you get_____ completely free.

A．other

B．others

C．one

D．ones