____ you really need it, it is better not to use free Wi-Fi.

假如你是黄海大学历史系的二年级学生李明，请写信给你校的Smith教授，代表学生会邀请他于五月份某周六给同学们做一场关于欧洲历史的讲座。具体题目请Smith教授自定，讲座时间约一个半小时，之后安排半小时的问答环节。

I think there will be a day when digital cameras will substitute for traditional ones.

What the old need most is that their children show much concern to them.

To my surprise, the machine made sixty years ago is still in use in this factory.

Senior management seem to be completely out of touch with their staff’s needs.

It was ___________ (care) of him to leave the door unlocked when nobody was in.

It is harmful to people’s health to take in too much salt and sugar every day.

If the industry doesn’t ____________ (modern), it will not survive.

Children should be taught how to ___________ (behavior) themselves.

He is known as a ___________ (report) throughout the country.