It’s necessary for you to _____ at least an hour each day to learn the new vocabulary.
_____ to nuclear radiation, even for a short time, may produce variants (变异体) of genes in human bodies.
The discovery of new evidence led to _________.
You have made a ______. You have _____ two lines from this paragraph
He _____ to the meeting ten minutes earlier, but he was _______ by a heavy fog.
– I wonder if you could go with me to the cinema.--- Don’t disturb me. I ______ a composition all the morning and haven’t finished it yet.