Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.

Higher education is very importance to national economies, and it is also a source of trained and educated personnel for the whole country.

A. Had the letters typed

B. Have the letters typed

C. Have the letters been typed

D. Have been the letters typed

A. they keep the users alert all the time

B. they are indispensable in everyday communications

C. they make them look more stylish

D. they cannot be replaced by regular phones

A. would be

B. was

C. had been

D. were

A. which

B. what

C. when

D. where

A. have lost / left

B. have lost / leave

C. lost / have left

D. were losing / had left

A. didn’t bring

B. wouldn’t have brought

C. hadn’t brought

D. won’t bring

A. applied/ had asked

B. applied/ asked

C. had applied/ asked

D. applied/ have asked