下列各句中，加点的成语使用恰当的一项是(　　)

Peter , where did you guys go for the summer vacation?—-We________ busy with our work for months, so we went to the beach to relax ourselves

If you plant watermelon seeds in the spring, you _____fresh watermelon in the fall. [ ]

How long may I ________ your dictionary—For one week.But it mustn’t ________ to others.

Stephen Hawking believes that the earth is unlikely to be the only planet_______life has developed gradually.