Find the one mistake (A, B, C or D) in these sentences and then correct them

The waiters asked (A) if we were all (B) one another (C) so we explained (D) that we were two separate parties.

Choose the best answer A, B, C or D for each sentence

By the end of last summer, the farmers _______ all the crop.

The old man walked (A) home (B) by himself, (C) in spite of he knew (D) that it was dangerous.

The director already _______ for the meeting by the time I got to his office

How many cities you and your uncle _______ by July last summer?

She (A) left her job soon (B) to devote (C) more time (D) into her family.

(A) Not only (B) she turned up (C) late, she (D) also forgot her books and pens.