[영어] 4.빈칸

Every day, the Earth saves our lives but every day, it threatens us. We are probably already fully aware of the dangers the Earth poses us. Volcanoes, earthquakes, blizzards and all the rest, we already know. But ________, most of us are unsure if we know fully. It's the harmful, sometimes radioactive material that comes from all directions, usually and most surprisingly, the Sun. The ozone, the atmosphere and the Earth itself shield us from these nasty materials. Then what we should unanimously worry about is how much the ozone layer is being opened up. The preon gas(CFC) we create chemically, combines with ozone(O3) to make Chlorine Oxide(ClO) and oxygen(O2) and in the end, breaking up the ozone layer. This makes life on Earth perilous not only for humans, but for all living things that inhabit our beautiful planet.

.1. what it saves us from
.2. how powerful these dangers are
.3. how fragile these ozone layers are
.4. which of these dangers are the most perilous
.5. what these interstellar materials protect

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