By the end of this month, we surely a satisfactory solution to the problem.

A) had seen B) has seen C) sees D) saw

A) is B) have been C) has been D) are being

A) and so her brother did B) and so did her brother

C) and too her brother D) and did her brother ,too

A) who B) that C) what D) which

A) which B) where C) when D) that

A) when B) before C) since D) as

A) what is needed B) for our needs

C) the thing needed D) that is needed

A) which B) who C) as D) where

A) provided B) unless C) until D) lest

A) For B) Since C) Before D) While