—No, never, but I went to Canada a few years ago.
A:Have you been
B:Have you gone
C:Did you go
D:Will you go
mA(g)+nB(g)⇌pD(g)+qE(s)H<0(m、n、p、q为最简比例的整数).
2011年11月1日5时58分10秒,神舟八号无人飞船顺利发射升空.这说明( )