网址：http://m.1010jiajiao.com/timu_id_2730544[举报]
—When did the Shanghai Expo open?
—_______May 1st, 2010.
A．In B．On C．At D．By
A：When did the Shanghai Expo open?
B：________ May 1st, 2010．
A．In
B．On
C．At
D．By
