—How was your summer holiday, Lily?—I went to Beijing with my parents and we _________ a good time there.
A:have
B:had
C:have had
D:will have
试管内壁残留下列物质,用稀盐酸浸泡不能除去的是()
若一组数据1、2、3、x的极差是6,则x的值为( )