be casual about　　　　　　 对......漫不经心

　　a casual meeting 巧遇

　　a casual visitor 不速之客

　　casual clothes 便装

　　①We had a casual meeting in the bank that day.

　　那天我们在银行巧遇。

　　②As I know, some American young people seem to be casual about clothes.

　　据我所知，有些美国年轻人对穿着很随便。

　　③I was going out when I had a casual visitor.

　　我正要出门，这时来了一位不速之客。

　　2．(教材P9)It was obvious that he was suffering great pain when he talked.

　　显然，他说话的时候遭受着巨大的痛苦。

　　obvious adj. 显然的，显而易见的

　　(1)It's obvious that ...　　　 显然......

　　for obvious reasons 由于显而易见的原因

　　be obvious to sb. 对某人是显而易见的

　　(2)obviously adv. 明显地，显而易见地

　　①It was obvious that he was telling lies to us.

　　很显然，他正在对我们撒谎。

　　②The mistake was obvious to all (those) present.

　　所有(那些)在场者一眼就能看出那个错误。

　　③Obviously (obvious), we don't want to spend too much money.

　　很明显，我们不想花太多的钱。

　　3．(教材P9)If you continue to behave like this, you'll have to answer for your behaviour.

　　如果你继续这么做，你要为你的行为承担责任。

　　answer for 对......负责，因......受到谴责；担保(某人的品质)等

　　①You'll answer for your rudeness one day if you don't follow my advice.

　　如果你不听我的劝告，总有一天你会因你的无礼行为而受到惩罚。

　　②I will answer for it that he can accomplish the task on time.

　　我愿意担保他能按时完成这个任务。