Question

[Lê Quỳnh Anh]

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.

The improvement (A) for water standards (B) over (C) the last 50 years has been (D) very great.

A. for water

B. over 

C. the last

D. very great.

Answer 1

[Dương Hoàn Anh]