1. I spent the whole day in my room, but I did not write a single card!
    我在屋里呆了一整天，可连一张明信片也没写成。

2. It is as if a single unimportant event set up a chain of reactions.
    好像是一件无关紧要的小事引起了一连串的连锁反应。

3. I spent the whole day in my room, but I did not write a single card!
    我在房间里关了整整一天，然而竟连一张明信片也没写成！

4. In my family, success is weighed by a single standard: the ability to be first.
    在我家里，成功与否只由一种标准来衡量，这就是争取第一的能力。