Bộ câu hỏi: Hạ gục câu hỏi tìm lỗi sai (Buổi 3)

The system will be down for a few minutes since technicians are working on them.

11/30

The system will be down for a few minutes since technicians are working on them.

down

since

are

them

Giải thích

Chọn D