人教版八年级下册英语作业本Use should ,shouldn't,can ,must or mustn't to c

人教版八年级下册英语作业本
Use should ,shouldn't,can ,must or mustn't to compiete the sentences.
1.At crossroads,we always see the traffic lights.when ythe red light is on .we ___________.when the green light is on ,we _____.
2.when we find a big fire ,we ______
在人教版八年级英语作业本下册（1）第五页第二题