She has taught her children to play piano for 4 years.Đoạn văn40/40She has taught her children to play piano for 4 years.She started teaching her children to play piano 4 years ago.She started to teaching her children to play piano 4 years ago.She started teaching her children to play piano for 4 years ago.She started teaching her children to play piano since 4 years.Giải thíchĐáp án A