Can you explain why 90% chinese students didn't come back?I

Can you explain why 90% chinese students didn't come back?I Can you explain why 90% Chinese students didn't come back?问为 Can you explain why 90% Chinese students didn't come back?这该 why didn't you come here yesterday Can you explain it_______ You can’t come back?I don’t need you! I didn't know you had come back 中的had come 不该用have came back ---Alice,why didn't you come yesterday? Alice,why didn't you come yesterday? I can’t explain why I love Li Yuchun.If you hear her sing,yo ----Hi,nancy.I didn't know you had come back.So have you gra ----Hi,Nancy,I didn’t know you had come back.So have you gra Alice,why didn't you come yesterday?I _,but i had an unexpec