Unfortunately when I arrived, my friend ________ so we only had time for a few words. A. has just left B. was just leaving C. would just leave D. had just left

Unfortunately when I arrived, my friend ________ so we only had time for a few words.

A. has just left

B. was just leaving

C. would just leave

D. had just left

Công thức: When + S + Ved + O, S + had + PII + O

Dùng trong trường hợp 2 hành động cùng xảy ra trong quá khứ, ta dùng thì quá khứ hoàn thành cho hành động xảy ra trước và quá khứ đơn cho hành động xảy ra sau.