He was born _____ a winter afternoon.[ ]

一Are you going to Guilin by plane?一It’s fast but expensive, so I’m not sure．I ________ take a train．

I have two sisters. One is a teacher, ____ is a singer. .

Teenagers like reading the books ________ are written by Guo Jingming.

Look! These red shorts are _____ sale _____ only $8.[ ]