Tom and his sister ______ to the barbecue last Saturday.They were very happy.
A:have invited
B:were invited
C:were inviting
D:invited
有一包白色固体粉末,可能含有CuSO4、Ba(NO3)2、BaSO4、Na2CO3、KCl中的一种或几种,某同学对其组成进行了探究,过程如下:
根据以上实验操作与现象,该同学得出的结论不正确的是( )