Parents complain their children are behaving unreasonably _____children consider their parents to be old-fashioned.
Scientists are warning that ________ emissions of carbon (碳排放) are cut, we could be heading for an environmental disaster.
——Did you inform Helen of the plan put forward at the meeting?—Of course. ________ I saw her.
Please call my secretary to arrange a meeting this afternoon, or ________ it is convenient to you.
She usually keeps her valuables, such as jewels and money, ________ she believes secure.
How can they expect to learn anything ________ they never listen?