刘禹锡，字梦得，河南洛阳人。与柳公权交谊很深，诗文并重，人称“刘柳”；又与白居易唱和甚多，并称“刘白”。（）
参考答案：错
--- Excuse me, I was told I could find Professor Li here.
--- And you ______. Anything I can do for you?
A． have
B． had
C． did
D． do
一根长为0.1m、通有电流1A的导线，垂直放在磁感应强度为2T的匀强磁场中，受到的安培力大小为（ ）
A．0
B．0.2N
C．0.4N
D．0.5N
