A. 单句改错：请找出并改正下列句子中唯一的一处错误。
1. Good habits lead us to and a good future. ______
2. We'd better more fruit and vegetables. ______
3. Keep away from smoke. ______
4. In a word,we should try to develop a lifestyle to build up a strong body. ______

A. 1. Good habits lead us to success and a good future.
2. We'd better eat more fruit and vegetables.
3. Keep away from second-hand smoke.
4. In a word, we should try to develop a healthy lifestyle to build up a strong body.

B. 句式升级：请根据要求完成下列句子。
1. Don't eat too much junk food. It's not good for our health.(用because改成复合句)
2. Third,to have enough sleep is very important.(用“It is+形容词+to do sth.”改写句子)
3. We should go to bed early and get up early. We can have a good rest.(用so that改成复合句)

B. 1. Don't eat too much junk food because it's not good for our health.
2. Third, it's very important to have enough sleep.
3. We should go to bed early and get up early so that we can have a good rest.

Good morning,everyone. It's important for us to live a healthy life.First of all, we need to form good eating and living habits. It's good for us to have a big breakfast. We'd better eat more fruit and vegetables. It's healthy for us to have enough sleep.
Second, it's necessary for us to do more exercise. We can ride or walk to school. We should take an active part in all kinds of activities. Keeping clean is also important. So we must wash our hands often to prevent some diseases from spreading.
Last but not least, we'd better have a good mood. As teenagers, we should be outgoing and help each other. We should pay no attention to others who laugh at us.
In a word, the healthier life we live, the happier we will feel.

One possible version:
Good morning, everyone. It's important for us to live a healthy life.
First of all, we need to form good eating and living habits. It's good for us to have a big breakfast. We'd better eat more fruit and vegetables. It's healthy for us to have enough sleep.
Second, it's necessary for us to do more exercise. We can ride or walk to school. We should take an active part in all kinds of activities. Keeping clean is also important. So we must wash our hands often to prevent some diseases from spreading.
Last but not least, we'd better have a good mood. As teenagers, we should be outgoing and help each other. We should pay no attention to others who laugh at us.
In a word, the healthier life we live, the happier we will feel.