-- What did Tom say to you just now, John?
-- He asked .
A:why I am so happy today
B:what will I do for the weekend
C:who did I play football with after school
D:if I could go to the movie with him tonight
下列单摆的周期相对于地面上的固有周期变大的是 ( )
1856年,英法帝国主义发动了____。