Take the exam carefully, _______ you won’t get full marks.

—Do you have the same hobby with your brother?—No. I like collecting stamps _______ he likes reading. 

The earth will become worse and worse ________ we do something to stop her from being polluted.

       she likes chatting, she is careful about making friends with strangers online.

—When are you going to fly to Taiwan this summer?—_________ we finish school. It will be a great holiday.