1. The United Nations has (ООН в единственном числе) meetings where world leaders agree on what to do about global warming. If there is too much pollution in the air, some people have (conditional - как факт.Если будет 1-ое условие, то точно произойдет 2-ое) health problems.
2. Ecologists looked for special spots on white pine trees to know if there
were(согласование времен, множественное число) high levels of ozone.
3.Many types of air pollution are invisible, but some can be seen(пассивный залог) with the naked eye.
4. The teacher asked the boys if they had done(согласование времен в косвенной речи) the task.
5.Satellite images proved that deforestation had increased (согласование времен) rapidly.
6.The passage is so difficult that I can't (по смыслу) understand it.
7.Experts said that less than 3 per cent of the water on Earth was(согласование) fresh water.
8.His health has improved since he returned (грамматические правила) from the hills.
9.If we had sorted the waste, we would have saved (3 conditional) millions of kilowatts of energy.
1. The United Nations has (ООН в единственном числе) meetings where world leaders agree on what to do about global warming. If there is too much pollution in the air, some people have (conditional - как факт.Если будет 1-ое условие, то точно произойдет 2-ое) health problems.
2. Ecologists looked for special spots on white pine trees to know if there
were(согласование времен, множественное число) high levels of ozone.
3. The teacher asked the boys if they had done(согласование времен в косвенной речи) the task.
4.Satellite images proved that deforestation had increased (согласование времен) rapidly.
from abroad
arrived
plane
waiting-room
announcement
landed
Customs-office
declare
go through the customs
flight
flew
felt well