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
According to scientists (A) who study birds,(B) upon hatching,(C) ducklings have already known to swim.(D)
A. scientists
B. birds
C. upon hatching
D. to swim
Đáp án D.
“to swim” -> “how to swim”: upon hatching, ducklings have already known how to swim (trước khi nở, vịt con đã biết được bơi như thế nào