Ans 1.

“Many people are earnestly studying in the library.”(x)
“Many people are earnestly studying in a library.”(○)

Ans1.

Ans2.

Ans 2.

Ans 3.

Ans 3.

Ans 4.

Ans 4

Ans 5.

Ans 5.

“Two girls and one boy are using a selfie stick to take photos outdoors at what seems to be a tourist spot.”

Ans 6

Ans 6.

Ans 7.

Ans 7.

Ans 8.

Ans 8.