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一、单项选择题(共30小题,每题2分,共60分)阅读下列材料及太阳系九大行星与公转周期图(图1),回答1~3题。“发射窗口”是指运载火箭发射时比较合适的一个时间范围。这个范围的大小也叫发射窗口的宽度。宽度有宽有窄,宽的以天计算,窄的只有几分钟甚至几十秒钟。是根据地面观察、?
First, single-choice questions (30 questions in total, 2 points for each question, a total of 60 points) Read the following materials and the solar system nine planets and revolution cycle diagram (Figure 1), answer 1 to 3 questions. “Launch window” refers to a suitable time range for the launch vehicle to launch. The size of this range is also called the width of the launch window. The width is narrow and wide, the width is calculated in days, and the narrowness is only a few minutes or even tens of seconds. According to the ground observation,?