_____, experts point out that students can easily fail at starting their business because of a lack of preparations.
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.
In much of the animal world, night is the time ______ for 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.
Michelle found a job as a high school teacher which _____ spending quite a lot of time with students.