19、 break.    A. bread  B. meat   C. tea      D. great

17、A thousand thanks for your_____（邀请）to pay you a visit in spring.

16、Next day was to be a great mass-meeting in ___（庆祝）of their revolution.

15、We should try to settle this affair by  _____（争论，讨论）and not by fighting.

14、Have you _____（吸收，消化）everything that is important in the book?

13、 A _____（化学）change takes place in paper when it burns.

12、The brain performs a very important _______（作用）;it controls the nervous system of the body.

11、Even after hours of work his ____（精力）never seems to give out..