Mark the letter A, B, C, or D on your answer sheet to show the underlined part that needs correction.

Câu hỏi

The center has been researching into the cure for the COVID-19 virus ever for the outbreak of the pandemic.

Đáp án
B. ever for

Câu hỏi thuộc Bài tập:

E10- I-learn- Unit 4 (2)