. Today, housework has been made much easier by electrical _____.
Water, _____ we cannot live, exists in the form of liquid, gas or solid.
His laziness ___________ his failing in the exam.
As we all know, smoking ___________ people’s health.
_____ you have worked out the first problem, you may go on to work on the second.
Most of the evidence was destroyed in the fire. _____, it would be almost impossible to prove Jim guilty.