13.It gives rise to (lead to / bring / create) a host of problems (consequences).
14.There are numerous reasons why …, and I shall here explore only a few of the most important ones.
15.It will exert (have / produce) profound (far-reaching / remarkable / considerable / beneficial / favorable / undesirable / disastrous) effect (influence) on…
16.A multitude of factors could account for (contribute to / lead to / result in / influence) the change (increase / decrease / success/ failure / development) in…
17.In 1999, it increased (rose / jumped / shot up) from 5 to 10 percent of the total (to 15 percent / by 15 percent).
18.By comparison with 1998, it decreased (dropped / fell) from 10 to 5 percent (to 15 percent / by 15 percent).
19.It account for 15 percent of the total.
20.There were 100 traffic accidents in April, and increase of 5 percent in a five-month period.
21.By 1999, only (less than / more than / almost / about / over / as many as) three quarters (40 percent of / one out of five / one in four) college population (graduates / housewives) as against (as compared with) last year (1998) preferred to (liked)…