Despite being one of the most famous and frequented attractions in the United States,
We don’t really know how old it is
It has long been believed that the Colorado River began carving the Grand Canyon about 6 million years ago,
Of all Grand Canyon facts, this one is pretty cool—no word-play intended. Sudden changes in altitude have an enormous impact on temperature and rainfall, so the weather you are experiencing could differ dramatically, depending on where you are in the Grand Canyon. The coldest, wettest weather station in the region is the Bright Angel Ranger Station on the North Rim, while the hottest (and one of the driest) is just 8 miles away at Phantom Ranch.
There are lots of fossils in the area
While the dinosaur might have missed out on seeing the Grand Canyon, lots of other fossils have been found.
Fish are relatively uncommon in the area
Prior to modern flood control measures, the Colorado River provided a uniquely difficult habitat for fish, with heavy mud with small rocks, frequent floods, and temperatures ranging from extreme heat in summer to sub-freezing in winter. Consequently, only eight fish species are native to the Grand Canyon,
A.but a 2012 study contained a real shocker |
B.and many other species are found outside this area. |
C.and six of them are found nowhere outside of the Colorado River. |
D.The weather in the Grand Canyon is really cool. |
E.This indicates that other creatures frequented the location. |
F.The Grand Canyon creates its own weather. |
G.Grand Canyon National Park still holds some surprises. |

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

