1. You have to be careful.你得小心。 疑点：be careful“小心，当心”
如：Be careful while crossing the road.过马路要小心。
难点：be careful后常跟of短语。与它同义的有look out。
如：Aren’t you a bit too careful of your health？你对个人的健康难道不是有点过于小心了吗？
Look out！There’s danger ahead.当心！前面有危险。
2. At times an ad can lead you to buy something you don’t need at all.有时广告可能导致你买你根本不需要的东西。
