问题
选择题
“How long do you suppose it is _______ he left for Japan?” “No more than half a month.”
A．when
B．before
C．after
D．since
答案
D。
问句的基本结构是“It is +时间段+since 从句”，其原句型是 I suppose it is no more than half a month since he left for Japan. 假若对此句中的 no more than half a month 提问，则可得到提问句。