Young people go to college with the expectation that ____________ educated people get a higher pay.
He______ on the grass, looking at the clouds in the sky.
The country life he was used to _______greatly since 1992.
Most birds find it safe to sleep in the trees, but _______they have eggs or young chicks, they don’t use a nest.
_______ boys and girls in that school are almost equal.
Every possible means ______to prevent the air pollution, but the sky is still not clear.