Questions

When modifiers are misplaced or put in the wrong place, things can get quite confusing. A modifier adds detail or limits or changes the meaning of another word or phrase. 

Here Option A) "Covered in fluffiness, the couple played with the kitten" is the ony sentence contains a misplaced modifier. In the sentence, it gives the meaning that the couple are fluffy not the kitten.

State-run NTPC said the company has forayed into electric vehicle charging business and has set up first such charging stations at its offices in Delhi and Noida. Adding that the move will push demand for electric vehicles, an official said, "The main objective in setting up the charging points is to be part of promoting clean energy transportation."

It will stop at a height where the weight of the balloon with contents is equal to the weight of air displaced by it, i.e , when the upthrust is equal to the downthrust. The question of bursting will depend on how much difference of pressure inside and outside , the material of the balloon can withstand. It is assumed the balloon is filled with a lighter than air gas like hydrogen or helium.

In the above given sentences, only option C) The hen has laid 10 eggs is gramatically correct.

A) Not correct - We had gone to the party last night

Correct - We went to the party last night

B) Not correct - I have seen him yesterday

Correct - I saw him yesterday (We do not use the present perfect tense with past time expressions.)

D) Not correct - She is sleeping for 2 hours

Correct - She has been sleeping for two hours. (We use the present perfect continuous tense to show duration.)