Choose the letter A, B, C, or D to complete each of the following questions. I and my younger sister __________ English since we were in grade 3.Đoạn văn17/40Choose the letter A, B, C, or D to complete each of the following questions. I and my younger sister __________ English since we were in grade 3.studiedhas studiedhave studiedhad studiedGiải thíchC. have studied