A:15
B:25
C:55
D:35
I can tell you more about Thanksgiving Day.(变为否定句)
I ____ ____tell you more about Thanksgiving Day.
5月31日是“世界无烟日”。吸烟有害健康,烟草中的尼古丁能杀伤大量精子,降低受孕率。人产生精子的器官和受精场所分别是( )
设集合M={x|x2﹣2x﹣3<0},N={x|log2x<0},则M∩N等于( )