Electricity, like other forms of ______, has greatly increased in price in recent years. 

She had a guilty________ about not telling the police what had actually happened.

Some countries are increasing their use of natural gas, and other forms of __________. 

—How did you do in the driving test yesterday? —I had a narrow ______. My month-long practice gave me some comfort.

It’s known to all that the_____ of life is full of hardships.