翻译几句英语句子(中译英)

你的五句话：

1. Not until his mom came back did he go to bed.
强调句是 It's not until his mom came back that he went to bed.
还有：He didn't go to bed until his mom came back

2. It's Tom who saved the old man at expense of his own life.
3. It is because of the reason known to all that American diet is majorly made of meat and potatoes.

1. He didn't go to sleep until his mother came back.
2. It was Tom that saved this old man at the cost of his life.
(It was...that...强调句结构)
3. Because of a well-known reason,American diet is made up with meat and potatoes.

1, he did not go to bed until his mother be back.

2, It just tom save the old man with the life of himself.

3, It is well known that American's food and drink are formed by potato and meat.

At last, work hard, day day up, thanks.

1.He didn't went to bed until his mother came home.

2.It was Tom who saved the old man at the cost of his life.

3.As is known, American diet is made up with meat and potatoes.
楼上有几个纯属机译，直接不对！~

1.It was not until his mother got back that he went to sleep
2.It was Tom who saved this old man at the cost of his life
3.It is because of a well-known reason that American diet is made up with meat and potatoes.