MARK THE LETTER A, B, C OR D ON YOUR ANSWER SHEET TO INDICATE THE COR...

Câu 11: Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to the following question.

________ the attic, they came across a valuable vase.

A. While the Smiths are cleaning up B. The Smiths cleaning up

C. While the Smiths were cleaning up D. As the Smiths have cleaned up