Oh! I you in Beijing.How long have you been here?
A. don’t know.. were
B. hadn’t known.. were
C. haven’t known.. are
D. didn’t know.. were
网友回答
A. don’t know.. were
B. hadn’t known.. were
C. haven’t known.. are
(答案→)D. didn’t know.. were
解析：可联系答.案.网客服索取。