A:will have had
B:will be having
C:will have
D:is having
—Sorry, she isn't at home at the moment. _______?
I don’t like the milk. It’s cold.
按图示的规律搭下去,则所用火柴棒数an 与所搭三角形的个数n之间的关系式可以是____.
如下图,AB和CD互相____,____是CD的垂线,____是垂足.