Chuyên đề 3: Multiple choice ( Vocabulary and Structure )

then what I know yesterday, I would have saved myself a lot of timeand trouble over the years.

198/378

            then what I know yesterday, I would have saved myself a lot of timeand trouble over the years.

Had I known

Did I know

If I know

If I would know

Giải thích

Chọn đáp án A