Be careful when ______ the road.A.crossingB.to crossC.cross

________ when you cross the road.A、Do careB、CareC、Do be carefulD、To be careful

Care must be taken to condition the ______ in the boiler to prevent scaling, and corrosion

You ______ be too careful when you drive a car in the rush hour.A．might notB．must notC．can

The sentence that expresses REQUEST is______.A．Pass me the salt,please.B．Be careful with t

In doing experiments, you must be ______ the precision instruments.A．more than careful wit

Teachers can hardly be______careful when they instruct a lesson.A．veryB．enoughC．tooD．so