100 câu trắc nghiệm Thì quá khứ hoàn thành tiếp diễn (Past Perfect Continuous) có đáp án

Timothy ________ networking courses for two years when he was promoted to be a coach.

52/100

Timothy ________ networking courses for two years when he was promoted to be a coach.

had taken

had been taking

have been taking

could have taken

Giải thích

Chọn đáp án: B