一、开头与结尾

A good beginning makes a good ending.（善始者善终）

A bad beginning makes a bad ending.（不善始者不善终）

A bad thing never dies.（遗臭万年）

The best time to plant a tree was 20 years ago. The second best time is now.（种树的最佳时机是20年前，其次是现在）

二、因果关系

The harder you work at it, the more progress you will make.（你越努力，进步越大）

If everyone makes a contribution to protecting the environment, the world will become much more beautiful.（如果每个人都保护环境，世界将更美好）

We should be very grateful if you help our children with their English study.（如果你帮助我们孩子学英语，我们将感激不尽）

三、对比与转折

Compared with cars, bikes have their advantages and disadvantages.（与汽车相比，自行车优缺点并存）

Although computers bring people a lot of convenience, they have many disadvantages.（尽管电脑带来便利，但也存在弊端）

Just as every coin has two sides, technology also has its pros and cons.（正如硬币有两面，技术也有利弊）

四、建议与呼吁

We must protect the environment to ensure a sustainable future.（我们必须保护环境以确保可持续发展）

Education is the key to personal and societal development.（教育是个人和社会发展的关键）

Let's work together to create a harmonious society.（让我们共同努力创造和谐社会）

五、经典表达

A bird in the hand is worth two in the bush.（一鸟在手胜过双鸟在林）

The early bird catches the worm.（早起的鸟儿有虫吃）

Knowledge is power.（知识就是力量）

这些句子可用于作文的开头、结尾或段落中，帮助丰富内容并提升语言表达能力。建议考生结合具体话题选择合适句子，并注意语法和语境的适配性。