"approve of" vs. "approve"

[Myc]

When do you use "approve of" vs. "approve"

Why does the author use approve of in this sentence. This is from REA PSAT 2006 edition pg. 43 #7.

Three hundred years ago John Milton protested... laws which required a government official to approve of any manuscript before it was published.

can't you also say:

Three hundred years ago John Milton protested... laws which required a government official to approve any manuscript before it was published.

also why did they use "which" ? Since requiring a government official to approve any manuscript is important, shouldn't you use "that"?

Thanks

[Yankee]

Hi myc

Using approve of sounds more like a personal judgement that something is acceptable. Using approve would sound more like giving official permission/authorization.

You can use either that or which to introduce the defining relative clause in your sentence. Using that would probably be more common.

Amy