---TheylikeplayingfootballSaturday.---______.A.SoareweB.SoweareC.SodoweD.

---They like playing football Saturday.---______.A.So are weB.So we areC.So do weD.So we do

C解析此题考查“So+助动词+主语”的用法．“So+助动词（be, do, can, have…）+主语”结构表示“与……同样”．例如：
He is English. So is she.他是英国人，她也是英国人．
They like P. E. So do we.他们喜欢体育，我们也喜欢．
He can skate. So can Lily.他会滑冰，莉莉也会．
They have studied English. So have we.他们已经学英语了，我们也学了．
注意：“So+主语+助动词”表示“的确知此”，与“So+助动词+主语”是完全不同的用法．例知：
He is good at swimming. So he is.他擅长游泳，他的确如此．

谢谢解答