As soon as his teacher begins lecturing, he begins to doze off, not intentionally but _____.
There is a 20 minute parking _____ here, so we must get back to the car very quickly.
Because of the poor harvest, wheat prices have _____ in the last six months.
I can't advise you what to do. You must use your own _____.
Tell your brother to come _____, because it's going to rain in a minute or two.
A successful scientist needs _____ if he wants to make hypothesis (假设) of how processes work and how events take place.