Choose the grammatically correct sentence: We had to sign there, have not we?

Choose the grammatically correct sentence: The two kind of cake are available now.

Choose the grammatically correct sentence: He has not completed the assignment, neither have I.

Choose the grammatically correct sentence: Let us go to home, did we?

Choose the grammatically correct sentence: The call is going busy, someone have be on another telephone.

Choose the grammatically correct sentence: The pen was not write, it must run out of ink.

Choose the grammatically correct sentence: She used speaking in public.