Going to the movies____ one of the most popular.......空格要接 is 還是 are?

答案是is，原因為going動名詞當主詞，其動詞用單數，因其有動詞特性，所以to the movies介詞片語當副詞修飾going.以上是文法解析，另外不定詞片語及that引導名詞子句當主詞，用法相同。To go to the movies is ………

Going to the movies (is) one of the most popular.......

理由 :
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Going to the movies (is) one of the most popular.......
= The entertainment of going to the movies is one of the most popular.......
= This entertainment (going to the movies) is one of the most popular.......

「看電影」是一種娛樂, 所以是「單數」(singular) ---> ∴ 之後用 "is"

簡單點寫, 這句就是 :
This entertainment is one of the most popular....... [而 "This entertainment" 就指 "going to the movies"]

is

In Grammar of the form used in writing of one thing as one subject as literally singular:-
eg:-Going to the movies (is) one of the most popular entertainment.
The reason:-
The entertainment of going to the movies (is) one of the most popular...
=The entertainment (going to the moviies) is one of the most popular...
(going to the movies)=is a present participle phrase, is a non-finite verb form that can be used in compound forms of the verb as an adjective;
Or Simply:-
going to the movies=singular
This entertainment=going to the movies
Hence;This entertainment=singular;
This entertainment (is) one of the most popular.....=singular.