So what's for [десерт] tonight?

dessert pudding afters

Info: Both "pudding" (in this sense) and "afters" are unknown in the US.

The mice have been [обгрызала] at the furniture stuffing.

Hint: Use the progressive form!

nibbling

Info: "Gnawing" is more for wood or hard food.

They bought the house incredibly [дешево] .

cheaply cheap

Info: Both "cheap" and "cheaply" work here.

The key [недостаток] in the plan was the lack of feedback.

flaw deficiency imperfection shortcoming defect failing