Modern humans have only existed for a relatively short time, and maybe we’d like to stick around a lot longer. But how can we do that?
Figure out climate change.
Figure out nuclear weapons.
A single nuclear weapon doesn’t pose a threat to all of humanity, but the thousands of them in the world right now certainly do.
Figure out asteroids(小行星).
If you want to know the terrible consequences for ignoring space borne threats, just ask the dinosaurs how well it worked out for them. Asteroids have the ability to cause massive extinction events, wiping out vast numbers of entire species.
A.The consequences can’t be avoided. |
B.Countries are joining hands to solve it. |
C.Now the chances of one nuclear explosion increase. |
D.The earth’s climate has changed for millions of years. |
E.While these kinds of events are rare, the risks are severe. |
F.And we can see the effects of climate change everywhere. |
G.We need to disarm as much as possible to reduce the risk of disaster. |

同类型试题

y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2


y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2

