Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions.
Trả lời câu hỏi dưới đây:
______, Edison didn’t have much schooling and he was taught by his mother.
- "when" đứng đầu câu thay thế cho mệnh đề chỉ thòi gian. sau "when" + N/ N=phrase/ + V-ing