501. You'd better look before you leap. 你最好三思而后行。
502. You know what I'm talking about. 我想你知道我在说什么。
503. He has been sick for three weeks. 他已经病了几周了。
504. He inspected the car for defects. 他详细检查车子有无效障。
505. I count you as one of my friends 我把你算作我的一个朋友。
506. I go to school by bike every day. 我每天骑自行车上学。
507. I have a large collection of CDs. 我收集了很多唱片。
508. I won't be able to see him today. 今天我不可能去看他。
509. I'll call a taxi in case of need. 如果需要的话,我会叫出租车的。
510. Is there any sugar in the bottle? 瓶子里还有糖吗?
511. It's a secret between you and me. 这是你我之间的秘密。
512. It's very kind of you to help me. 你帮助我真是太好了。
513. Let's divide the cake into three. 我们将蛋糕分成三份吧。
514. Patience is a mark of confidence. 耐心是自信心的一种表现。
515. Susan is going to finish college. 苏珊将完成大学学业。
516. That is my idea about friendship. 这是我关于友谊的看法。
517. The book you ask for is sold out. 你要的那本书已经售完了。
518. The boy was too nervous to speak. 那男孩紧张得说不出话来。
519. The play may begin at any moment. 戏随时都有可能开始。
520. The salve will heal slight burns. 这种药膏能治疗轻微烧伤。