512. It"s very kind of you to help me． 你帮助我真是太好了。

511. It"s a secret between you and me. 这是你我之间的秘密。

510. Is there any sugar in the bottle? 瓶子里还有糖吗?

509. I"ll call a taxi in case of need． 如果需要的话，我会叫出租车的。

508. I won"t be able to see him today. 今天我不可能去看他。

507. I have a large collection of CDs. 我收集了很多唱片。

506. I go to school by bike every day. 我每天骑自行车上学。

505. I count you as one of my friends 我把你算作我的一个朋友。

504. He inspected the car for defects． 他详细检查车子有无效障。

503. He has been sick for three weeks． 他已经病了几周了。