`48. A.` causing

Explanation: "Causing" is the correct choice because it properly fits the context of the sentence. The sentence is stating that the generation gap is caused by a lack of communication.

`49. D.` forcing

Explanation: The sentence is about contrasting a controlling approach with a more explanatory one, so "forcing" is the appropriate word here.

`50. B.` popular

Explanation: The word "popular" fits well as these topics are now more commonly discussed in family settings.

`51.` `C.` independent

Explanation: Children desire independence as they grow older, which makes "independent" the correct choice.

`52.` k nhìn rõ