What worried the child most was ______ to visit his mother in the hospital.A. his not allowing B. his not being allowedC his being not allowed D. having not being allowed
In much of the animal world, night is the timefor sleep-pure and simple.
Butterflies ______ a sweet liquid produced by flowers, which bees and other insects collect.
According to the law, all foreigners have to ______ with the local police within two weeks of arrival.
While intelligent people can often ______ the complex, a fool is more likely to complicate the simple.
Carbon dioxide, which makes a ______ between us and the sun, prevents heat from getting out of the atmosphere easily, so the earth is becoming warmer.