In 1862 the American black people won their struggle____ equal rights after many years’ fighting ________ the white.
Children growing up in a single parent family ______ to beaggressive and ill-tempered.
_____many times, he finally understood it.
Every year _____ money and energy is spent on environment protection.
I am not appealing for myself. I am appealing ________ all the ordinary teachers.
Nobody knows for sure what effect global warming has ___ our environment in the long term.