A:150mL 3mol/LKCl溶液
B:150m L 1mol/LAlCl3溶液
C:50mL3mol/LMgCl2溶液
D:75mL 1.5mol/LMgCl2溶液
选词填空。
playing, name, brother, read, good
My ____is Jill. This is my____. He can____. He likes ____football. He's a____ boy. I like him. We are happy.
已知a→=b→=a→-b→,则a→与b→的夹角为( )
一只不透明的袋子中装有“G20,峰,会”3个球,这些球除标注外都相同,搅匀后从中任意摸出1个球,不放回,搅匀后再从中任意摸出1个球,不放回,再从中摸出最后1个球.
如图,将△ABC绕点A逆时针旋转80°得到△AB′C′.若∠BAC=50°,则∠CAB′的度数为()