阅读下列短文，从每题所给的A、B、C和D四个选项中，选出最佳选项。
A
Depths of our Earth hold great wonders. Below we explore four deepest places on Earth.
Veryovkina Cave, Georgia
Its entrance is located 2，285 meters above sea level. In 2018, scientists reached its bottom at 2，212 meters down. They squeezed through tiny openings to get from one cave to another. Rockfalls and floods waited secretly at every turn. Scientists could develop new medicines from microorganisms found in cave samples (样本). Caves also record ancient life and past climates.
The Mariana Trench, the Pacific Ocean
The Mariana Trench, with the maximum depth of 11，034 meters, is the deepest part of Earth's surface. Pressure there is intolerable, but creatures like sea cucumbers (海参) still exist. Scientists exploring it can gain deeper insights into how plates move and why earthquakes and volcanoes occur.
The Dead Sea, the Middle East
The Dead Sea is the lowest point on land at about 1，400 feet (about 400 meters) below sea level. It's nearly ten times saltier than ocean water, so you literally can't sink in the Dead Sea! Scientists think it could go dry in a few decades. Despite its name, the Dead Sea holds life. A few kinds of algae (藻类) and bacteria love its salty water.
Lake Baikal, Russia
At the depth of 1，642 meters, Lake Baikal is the deepest inland body of water. The Baikal seal is the only known seal that lives in this world's deepest freshwater lake. Scientists study the lake not only for the solid stuff beneath it that records climate history but because it's in a zone where a plate is splitting apart, causing earthquakes.
21．What do we know about Veryovkina Cave?
A．It was discovered in 2018. B．Its pressure is far from bearable.
C．It is risky to explore. D．Its samples are of little practical value.
22. Where should scientists go to better know earth movement?
A．Georgia & Russia. B．Russia & the Pacific Ocean.
C．Georgia & the Pacific Ocean. D．The Middle East & Russia.
23．What do the four places have in common?
A．They have some signs of life. B．They are over a thousand meters deep.
C．They are results of climate change. D．They are all below sea level.
