“寸有所长,尺有所短”,这句话告诉我们的道理是( )
The news has spread all over the country ____ the spaceship succeeded in returning to the earth.
____ he works hard, I don’t mind when he finishes the experiment.
____, he does not know the answer.
We were ____ to go out for a camp ____ it began to rain.
____ several times, the young scientist still kept on doing his experiments.