1 . 阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式。

A small device, Moxie, has produced oxygen on the surface of Mars,    1     (bring) the chances of surviving on the red planet a step closer. Research published in     2     journal Science Advances reported that Moxie produced breathable oxygen in seven-hour-long tests conducted in various weather and atmospheric conditions last year. The research also found that even in       3    (extreme) harsh weather conditions like a Martian dust storm, Moxie     4    (continue) to produce high purity oxygen.

“This is the first demonstration of actually using     5    (resource) on the surface of Mars and transforming them chemically into something useful for a human mission,” Jeffrey Hoffman, a retired astronaut, said.

“The thin atmosphere on Mars is 96 percent carbon dioxide and much more     6    (change)than on Earth and the temperature can vary by 100 degrees, ” Hoffman said. “One aim is     7    (show) we can run Moxie in all seasons.”

The device, Moxie, uses some special pumps,     8     take in carbon dioxide. The gas     9    (heat) to 800°C and pressed to separate the carbon and oxygen. Carbon monoxide is sent out as waste while the pure oxygen is left behind.

Despite the challenges, Moxie has proved durable in the extreme conditions on Mars and scientists regard the test results     10     a great achievement.

2 . 阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式。

China's Chang'e 5 mission     1     (successful) delivered samples of moon rocks and dust to Earth on December 17, 2020. It marks     2     first time in 44 years that moon rocks have been brought back to our planet.

The sample capsule landed in Inner Mongolia     3     a little after 2:00 a.m. Thursday local time. The drop-off was the ending of a 23-day mission that began on November 23,     4     China sent up Chang'e 5 from a site on Hainan Island. The mission's goal was     5     (collect) at least four pounds of material and bring it back to Earth.

The material collected by Chang'e 5 was from a site in the northwest region of the moon's near side. This area was formed more recently, and the rocks here     6     (think) to be only about 1.2 billion years old now. That means scientists     7     (study) the material could learn more about the     8     (evolve) of the moon.

Although Chang'e 5 was a short mission, it was one of     9     (complex) projects undertaken by the Chinese space program so far. The country is far from done with the moon---Chang'e 6,     10     (it) second lunar sample return, is ready to launch in 2023 or 2024.

3 .         No one knows exactly     1     the earth began, as it happened so long ago.     2     , according to a     3     (wide) accepted theory, the universe began with a “Big Bang” that threw matter     4     all directions. After that, atoms began to form and combine to create stars and other bodies.
        Water     5     (appear) on other planets like Mars but, unlike the earth, it had disappeared later.     6     was not immediately obvious that water was to be fundamental to the development of life. What many scientists believe is that the continued     7     (present) of water allowed the earth     8     (dissolve) harmful gases and acids into the oceans and seas. This produced     9     chain reaction,     10     made it possible for life to develop.