Simple: I cut the paper
Continous: I am cutting this paper right now
Perfect: I have cut this paper recently
Prfect Continous: I have been cutting this paper for 3 hours
21) economist
22)to,to
23)efficient
24)to,on
25) self-employed
26) with
27) manufacturer
28)in ,to
29)in
30)into
31) production
32)for
33) profession
34)compete
35)made
36) on
37) the self - employment ; employers
38) economic
39) competition
40) products