Choose the present perfect or past simple: i (see) three police cars this morning (it’s still morning). after he (arrive) home, he (unpack) and (go) to bed early. a: what’s wrong? b: i (break) a glass! my grandparents only (know) each other for a few months before they (get) married. i (be) in london for three years. i love it here. we (see) julie last night. he (be) a teacher before he (become) a musician. when the boss (walk) into the room, we (know) someone was going to get fired. the children (break) a window in the school last week. he (see) that film last year. fill in the gaps with for or since. meredith has lived here 1997. meredith has lived here eighteen years. john has had the last july. he has had the ball eight months. molly has liked fairy-tales she was a tiny baby.

i (have seen) three police cars this morning (it’s still morning).

after he (arrived) home, he (unpacked) and (went) to bed early.

a: what’s wrong?

b: i (have broken) a glass!

my grandparents only (knew) each other for a few months before they (got) married.

i (have been) in london for three years. i love it here.

we (saw) julie last night.

he (was) a teacher before he (became) a musician.

when the boss (walked) into the room, we (knew) someone was going to get fired.

the children (broke) a window in the school last week.

he (saw) that film last year.

meredith has lived here 1997.

meredith has lived here eighteen years.

john has had the last july.

he has had the ball eight months.

molly has liked fairy-tales she was a tiny baby.

1) global warming believed__ (to believe) to be caused by the greenhouse effect. 2) the seas_are filled) with poison: industrial and nuclear waste, chemical fertilisers and pesticides. 3) if nothing done) about it, one day no animal or plant will be able to live in the seas. 4) tons of harmful emitted daily) by industrial enterprises. 5) as globalization continues and the earth’s natural processes transform local problems into international issues, few left) untouched by major environmental problems. 6) acid rain, one of the most important environmental problems of all, cannot be seen). the invisible gases that cause acid rain usually come from automobiles or coal-burning power plants. 7) air pollution can have serious consequences for the health of human beings; the natural ecosystems are affected) severely by it.