Mark the letter A, B, C, or D on your answer sheet to indicate the cor

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions.    

Sometimes it is ________  to find suitable books for our children.

• A. A. difficult
• B. B. difficulty
• C. C. difficulties
• D. D. difficultly

Trước chỗ trống là động từ to be => cần tính từ => A