1. Anyone who is caring and helpful, and has a flexible(灵活的) schedule is welcomed to join us.
2. Usually popular science books explain basic principles(原则) of nature in a simple and interesting way.
3. A balanced diet and everyday exercise will keep us fit and energetic(精力充沛的).
4. In our society respecting the old and cherishing the young is a traditional virtue(美德).
5. Traffic accidents(事故) also arise, threatening the safety of road users.
6. With people’s incomes growing, there has been a sharp(急剧的) increase in the number of vehicles.
