I read in a grammar book that says all relative adverbs, including where,
when, how..., can all be replaced with "that."

This rule is incorrect!

It gave examples like:

(1) This is the ingenious way in which Roger assembled a radio receiver.

= This is the ingenious way that Roger assembled a radio receiver.

How cannot be used as a relative adverb.

This is the ingenious way in which Roger assembled a radio receiver.

This is the ingenious way that Roger assembled a radio receiver.


*This is the ingenious way how Roger assembled a radio receiver. (incorrect)

(2) These young people were born the year when (=in which) the first atomic
bomb was dropped on Hiroshima.

= These young people were born the year that the first atomic bomb was
dropped on Hiroshima.

(3) I'll go anywhere where (=to which) you take me.

I'll go anywhere where you take me.

The above sentence is grammatically correct, but I am not sure if it's
acceptable.

I'll go anywhere to which you take me.

The above sentence sounds strange.

When where is used as a relative adverb, it cannot normally be replaced by
that. Only when the antecedent is place, somewhere, anywhere, everywhere or
nowhere can the relative adverb where often be replaced by that.

(4) Watching TV is an activity where you are not required to do much thinking.

Watching TV is an activity that you are not required to do much thinking.

The above sentence sounds strange!

https://www.englishforums.com/English/ReplaceRelativeAdverbs/vcbxl/post.htm

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※ 編輯: perspicuity (111.241.146.213), 09/28/2016 03:09:28