She is a good girl ,as we all know.
她是一個好女孩,這一點我們都知道.
As we all know,he studies very hard.
正如我們大家所知,他學習很努力.
Politicians do it,too,as we all know.
政治家也做這個,我們都知道.
As we all know,smoking is very harmful.
大家都知道,吸煙非常有害.
要加,放前放后都加.
As we all know'Practice makes perfect.'
但是這個其實是并不用加的.
因為上面都是作為短語出現(xiàn)的.
加了也并不錯.
I‘m sure that .后面是一定沒有逗號的.
in other words 和in another word 一般都加,因為它們都是作為插入語出現(xiàn)的,為了區(qū)分于句子結(jié)構(gòu),通常要加.