CAE Part 3 - review

This fact (ABLE) us to sleep through the night.

Rather than enjoying (INTERRUPT) period of sleep at night, our ancestors had two naps.

We spend a really (COMFORT) night tossing and turning until morning.

The eight-hour-a-night pattern has become almost (ESSENCE) to modern humans.

It has only been (CUSTOM) in industrialised countries since the 19th century.

My eyesight became (PROGRESS) blurred.

This situation could be (SYMPTOM) of a stressful week.

After the 19th century (AFFORD) electricity was introduced which everybody could use.