It’s difficult-------- me to learn English well.

Some aspects of a pilot’s job__________ be boring, and pilots often ________ work at inconvenient hours．

All the cars ________ stop when the traffic light is red.

The school rules state that no child _____ out of the school, unless accompanied by an adult. 

We              have hurried all the way to the airport - the flight was called off because of the foggy weather．