It has been a long time for human to make _____ to reach the moon.
The radio you had got ______ went wrong again.
---Why did the teacher get angry? --- __________ what we had done the day before.
Did you ask whose computer ______________ ?
If you ____ your money ____ mine, we will have enough to buy one more set of stamps to ____our collection.
It was only with the help of the local guide ______.