11.  Now I changed a serious girl, with out smile on my face.

12.  The waste produced by industry should be done away with before it goes into rivers.

13.  Those companies which poluted the water resource must be deal with.

14.  At last , I thought we should search for the new source with the moden scientist .

15.  Third, with the developement of techonolgy many fatal illness can be deal with.

16.  The medicine can cure many difficult case which can not be treated with in the past.

17.  They had the waste-water delt with.

18.  Though the earth is covered with water on three forth surface, fresh water is limited.

19.  Each day there is a lot of work to do and lot of people to deal with.

20.  Although a bum with nothing is healthy .