选择下面给出的词填空(每个词可重复使用)

　　and　　but　　or　　so

She is ill (病了), ______ she can't come．

Xiao Ming is ill (病了). His mother is looking ________him.

[　　]

Xiao Ming is ill (病了). His mother is looking ________him.

[　　]

Xiao Ming is ill (病了). His mother is looking ________him.

1. A.
   at
2. B.
   after
3. C.
   for
4. D.
   down