Being examined twice a year, whether it is a car or a bus or a truck, is the rule that every driver _____ obey in this city.
Everyone knows that _____ is dangerous to play with fire, but _____ is difficult is to prevent children from playing with fire.
—I am thinking of the test tomorrow. I am afraid I cannot pass this time. —_________! I am sure you will make it.
As the clock struck nine, players ______their positions and the match began.
—Lucy, read this book, I ____ that you’ll be fond of it. —OK. I’ll read it after I have finished my homework.
The air is deadly polluted because some factories don't ________ the rules to protect the environment.