The old man sitting under the tree smiled dreamily, as if _____something pleasant in the past.
---Our family will go to Australia for a holiday. ---Oh, really? That sounds ________!
---“Why do you have to be there at six?” ---“The teacher demands that everyone _____in his seat at six.”
Some people waste a lot of food ____ others haven't enough to eat.
The new tax would force companies to __________energy-saving measures.
It is generally believed that constant reading and comprehending can ______ our mental ability of comprehension while physical exercise can help build up our body.