21.    The teacher divided class ________four groups.
 22.    He provide us ________a lot of useful information.
 23.    The ground is covered ________trash. You should clear ________all the trash.
 24.    Raw sewage is pumped directly ________the sea.
 25.    They are trying to save the animals ________extinction.
 26.    The world will end ________like a second-hand junk-yard.
 27.    I am looking forward ________hearing from you.
 28.    Don’t throw trash ________the water.
 Give the correct form of the verbs in brackets.
 29.    If the rice padddies are polluted, the rice plants ________________. (die)
 30.    If we ________on littering, the environment will become seriously polluted. (go)
 31.    What _________they ________________if they work hard today? (achieve)
 32.    If you ________________a chance to study in a foreign country, just take it. (get)
 33.    Plants ________________if they don’t get the sun and water. (die)
 34.    I am looking forword to ________________from you     (hear)
 35.    I suggest ________________by bus. (travel)
 36.    If you don’t study harder, you ________________the final exam. (not pass)
 37.    She ________________terribly sorry if he dies. (feel)
 38.    Go with me and I________________you my new car. (show)
 Supply the correct word form of the words in brackets.
 39.    The air in the city is very ________________ . (pollute)
 40.    Please listen to the lecture ________________. (care)
 41.    If the ________________ continues, what will happen? (pollute)
 42.    He was ________________ that they were not coming. (disappoint)
 43.    He is going to ________________all the bags. (collection)
 44.    We’ll make this beach clean and ________________. again. (beauty)