V/ FILL IN EACH NUMBERED BLANK WITH ONE SUITABLE WORD OR PHRASE. AC...

25.V/ Fill in each numbered blank with one suitable word or phrase. Acid rain will not be an easy problem (41) …………. . As more and more countries become(42) …………. , there will be more and more competition for petroleum for cars, home heating, andindusrty, while (43) ……… petroleum contributes greatly (44)………. acid rain, it is lesspolluted than coal. Unfortunately petroleum is more (45) ………. than coal and no one knowsexactly (46) …………. petroleum is left. Therefore, there will be a pressure to burn coal for energy.Coal is a (47) ……… dirtier energy source than petroleum. Since we already know how (48)…………. acid rain is, it is important (49) ……… we increase our efforts to find a (50)………. source of energy as quickly as possible, so that we can advoid further environmentaldamage.