例句： By doing extra homework, he soon got ahead of his class-mates.

例句： I hope I never set eyes on him again.

例句： Marriage is, first of all, a contract which must be governed by justice.

例句： He showed his sinister motive at last.

例句： The tourist complained that the room was too dirty.

例句： We are all not satisfied with the distribution of work among us.

例句： This system can regulate the temperature of the room.

例句： Punishment seemed to make no impression on the child.

例句： I gave Mary an apple in exchange for my favorite banana.

例句： reached out and touched the smooth stone.