Word Pairs


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When doom-and-gloom [merchants / merchandise] warn us about threats to our existence, we usually hear about climate change, asteroid [stricken / strikes] or nuclear war. Now scientists have warned of the [potentially / potential] threat from Earth's magnetic poles [flipping / flapping] upside down. The North Pole and South Pole are [responsibility / responsible] for creating a special barrier around Earth that protects [them / us] from killer radiation from space. All life on Earth depends [on / off] this shield. Without it, scientists say solar rays could cause [considerably / considerable] damage. The poles could flip in the next thousand years. This is because a rolling layer of liquid [irons / iron] under the earth's crust is changing direction. The revolving currents of this molten iron at Earth's center [acts / act] as a gigantic electromagnet.

[Historically / History] , Earth's North and South magnetic poles have flipped every 200,000 to 300,000 years. The last time was 780,000 years ago, [so / as] the next flip is well [overdue / overdone] . Some scientists say the flip could destroy satellite communications and [powerful / power] grids; that dangerous solar rays would greatly multiply rates [by / of] cancer; and that climate change could kill billions of creatures. Some scientists [forward / forewarn] that a polar flip could [even / ever] blow Earth's atmosphere away. However, one scientist dismissed the doom-mongers. He believes that the [affects / effects] of any increase in radiation would be as [harmful / harm] as lying on a hot beach for a day. He suggested a "floppy hat" would be enough to [protect / project] us from any increased radiation.

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