21.  If the condition of the soil is not good, you should improve it.

22.  In 533~ 544 AD, he wrote a book which included advice on improving the condition of sool , growing gree vegetables and furit trees, keeping cows and sheep, and keeping fish in lakes.

23.  If the condition of the soil is not good, you should improve it.

24.  Second you should examine the soil at your garden, if the condition of the soil is not good, you should improve it .

25.  He said that you must improve the soil if its condition is not good.

26.  I liked it very much because I wanted to improve our English level.

27.  I think it is useful for me to improve the listening.

28.  Miss Lin, can you give good iders to improve my listening except this?

29.  The radio will help me to improve my listening comprehension.

30.  I think everyone in our class wants to improve your lesson.