重点讲解：
1. lose weight
体重减轻；变瘦；
eg. She has been taking exercises to lose weight from day to day.
她每天锻炼来减肥。
eg. Many of us have tried to lose weight and failed miserably.
我们中很多人都努力要减肥，无奈均以惨败告终。
2. cut down on
削减；减少使用；
eg. We must cut down on the amount of material we use.
我们必须削减原料使用量。
eg. He has to cut down on the consumption of meat.
他不得不减少吃肉。
3. stick to
坚持不变；
eg. Lionel, you just tell the cops what you saw; stick to your story.
莱昂内尔，你就把自己看到的告诉警察，实话实说。
eg. f you stick to doing everything carefully, you catch sight of that you will close to the success.
如果你坚持认真的做每件事，你发现你将向胜利逼近。
4. put on weight
体重增加；变胖；
eg. You have put on weight.
你发福了。
eg. I was twelve, and starting to put on weight and grow taller.
我那时十二岁，体重开始增加，个子也开始长高了。
5. indulge in
（使自己）沉迷；放纵（自己）；
eg. They went into town to indulge in some serious shopping.
他们进城去大肆购物。
eg. But I happily indulge in their own world.
但我仍乐此不疲地沉醉在自己的世界。
