VOA慢速英语:Health: Now, an Update on Those New Year's Resolutions

replace和sbstitude都表示替代的意思，不过用法上有所不同：

substitute的用法是：substitute A for B，意为用A代替B；

replace 的用法是：replace A with B，意为用B代替A。

例句：
1. In manufacturing, cheaper materials are constantly being substituted for the better and more expensive kind.
2. The government decided to replace coal with gas.

还有一个词组可以表示替代的意思：take the place of sth，替代某物的位置。

2.That was compared to those who had never smoked.

compare to和compare with的区别：

compare to 和 compare with英语在使用当中可以对于我们而言相差不大，但其实意思上区别很大。这里涉及到语言的使用习惯、感知能力

1)compare…with意为“把……与……相比”，侧重指两者间的区别。

如：Compare this car with that one, and you will find the differences between them．
把这辆汽车与那辆汽车相比较，你就会发现它们之间的区别。

2)compare…to…意为“把……比作……”，着重注意两者间的相似点。

如：
This song compares our country to a big family．这首歌把我们的国家比作一个大家庭。

3)compare既可以单独用作及物动词，也可用作不及物动词。用作不及物动词时，以compare with…形式出现，表示“与……相比”。

如：
Living here can't compare with living in Shanghai．在这儿生活不能和在上海（生活）相比。

If you compare the two words, you can tell the difference between them.
如果你比较这两个单词，你就会辨别出它们之间的不同。

4)compared with…和compared to…都可用作状语，意义基本相同，可互换。如：

Compared to/with him, you are lucky.       与他相比，你是幸运的。
It was a small town then, compared to/with what it is now.  和现在比起来，那时它还是个小镇。

3.And the risk returned to normal after ten years of not smoking.

return to normal恢复正常

例句：The line is being rush-repaired and the power supply will return to normal in half an hour.
       线路正在抢修，半小时后恢复供电。 

4.The researchers say weight gain is probably to blame for the increase.

be to blame该受责备,应承担责任

例句：We ourselves were partly to blame.
      其中也有我们内部的问题。

要注意：这个短语本身就已经有被动的意思，表示某人应该受责备，应该承担责任，一定不要再用被动语态。

5.Another American study says obesity has become as great a threat to quality of life as smoking.

so+形容词+a/an+单数可数名词+that…也是结果状语从句的一种形式

This is so interesting a book that we all enjoy reading it. 这本书非常有趣，我们都喜欢看。

上面这句话可以更改为：This book is so interesting that we all enjoy reading it.