Some construction workers ______ the scaffolding high above the ground when the accident happened.

A. were to assemble

B. were assembling

C. had assembled

D. used to assemble

Đáp án
B. were assembling

Câu hỏi thuộc Bài tập:

FRIENDS PLUS 9 - ĐỀ KT THAM KHẢO - UNIT 1 – PRACTICE TEST 2