Did you ever see colored lights in the sky far (1) the earth Perhaps you saw these beautiful green, yellow, or red streaks (2) in the northern skies at night. Or (3) you have seen sheets or curtains of colored light. Sometimes the lights seem to wave in the wind. It is a truly amazing (4) . You may have seen the aurora borealis.
Some ancient people thought the lights (5) from goddesses riding through the sky with shining shields, but astronomers today know (6) . These scientists know that explosions on the sun cause the aurora borealis. From the explosions come (7) pieces of matter which spin around the earth. The small pieces cool and enter the earth’s air space and are drawn (8) the North and South Poles.
Once inside the earth’s air space, these small bits of matter (9) power in the form of light. Though you can see the aurora borealis only (10) , this amazing
A. last
B. end
C. begin
D. tell
| Black and white are two common words.
White means bright and purity, black is darkness and evil, but not always.
Sometimes the words are used differently. White hats and black hats represent
the traditional meaning of the words. The hats are symbols of the good guys and
the bad guys in American western movements. White hats and black hats had a real
purpose in the early days of motion pictures. The early movies were made with no
sounds. So the movie directors put a white hat on the hero and a black hat on
his opponent, the bad guy in the story. A black sheep is a person who does
things that are not accepted, that violate tradition. A black sheep is rejected
because he brings shame to his group. A family may have a member who is thought
of as a black sheep, a person who is not welcome at family gatherings. Black is also used i A. The Meanings of Different Colors. B. Colors and Jobs. C. The Meanings of Black and White. D. Expressions and Colors. [单选题]双塔干燥器通过去除系统中的水份并达到等于或小于（）的相对湿度
A.0.3 B.0.35 C.0.4 D.0.45 [单项选择]电流互感器的相位差是指其二次电流反向后的相量与一次电流相量的相位之差，当反向后的二次电流相量超前于一次电流相量时则相位差为（）值。
A. 正 B. 负 C. 不一定 [单选题]试验装置的低压回路中应有两个串联电源开关，并装设（）。
A.过载自动跳闸装置 B.漏电保安器 C.报警器 D.熔断器 [单项选择]CD13阳性见于（）
A. 急性B淋巴细胞白血病 B. 急性T淋巴细胞白血病 C. 急性粒细胞白血病 D. 急性红白血病 E. 急性巨核细胞白血病 [单选题]（ ）是列检作业场在列检作业中，实时记录作业信息的台账，是与车站办理列检作业技检时间等信息签认的依据。
A.《车辆检修通知单》（车统-23） B.《检修车回送单》（车统-26） C.《车辆破损技术记录》（车统-25） D.《列车技术检查记录簿》（车统-14A、车统-14B） 我来回答: 提交
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