Відповіді: Стр.75-(1)

1. For each question, choose the correct answer.

Water clocks

Ancient engineers developed many complicated clocks using flowing water to show time passing. Some of these involved building clock towers which were at (1 – c) least nine metres high. Similar clocks were in use right up until the last century in some parts of the world.

Twenty–first century scientists have (2 – a) researched how to create smaller, yet still environmentally friendly methods for keeping time. This has led to the (3 – d) invention–friendly Water–powered Clock, which uses tap water to create power for a simple battery. This means it doesn’t need to be (4 – b) plugged in, and the water in the clock doesn’t need to be replaced for six months, either. The clock has a digital (5 – c) display and because it is cheap to produce, this (6 – d) makes it easier to sell at a reasonable price, too.