逃逸系统也叫逃逸塔,它的任务是在火箭起飞前900秒到起飞后120秒_爱下问搜题

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问题单项选择题

逃逸系统也叫逃逸塔,它的任务是在火箭起飞前900秒到起飞后120秒时间段内，万一火箭发生故障，它顶端的11个火箭推进器可以拽着整流罩里的轨道舱和返回舱与火箭分离，并降落在安全地带，帮助飞船上的航天员脱离险境。如无意外，发射120秒后它必须准确脱离箭体，否则整流罩无法打开。据此用自然语言描述算法，下列哪一项是正确的（）

A.如果发射前900秒到发射后120秒火箭没有问题→那么就启动逃逸系统→否则发射后120秒整流罩打开

B.如果发射后120秒火箭有问题→那么就启动逃逸系统→否则发射后120秒整流罩打开

C.如果发射前900秒火箭有问题→那么就启动逃逸系统→否则发射120秒后脱离箭体

D.如果发射前900秒到发射后120秒火箭有问题→那么就启动逃逸系统→否则发射后120秒脱离箭体

答案

参考答案：D

完形填空

完形填空（共20小题，每小题1 分，共计20分）
Having lived in the house for so long, we found our kitchen looked    21   . We decided it was time to   22  the kitchen, and my husband and I were discussing   23  colors. The children, sitting nearby, suddenly all spoke together：“Not the measuring stick. ”
“No,” I   24   them. “Not the measuring stick.”
The measuring stick isn’t a (an)   25    stick but the kitchen side of the door between our kitchen and dining room. Along the edge we’ve   26   each child’s growth by making a mark showing his or her   27   on every birthday. Over the years, so many colored pens, pencils and    28     have been used that now, this white door is somewhat like an abstract(抽象的) painting.
Names and dates show different    29   , and I can tell by the script(手迹) who measured whom. An eight-year-old   30  to measure her three-year old sister, a grandchild measured her grandmother and my husband did the same to me. At our family    31   , when this door swung back and forth frequently, friends used to stop to    32    the names and dates. When they were asked if they would like to be always remembered, they    33    smiled shyly and went back right up into place,     34 to be measured.
Many of those   35    on the door are still   36   . Some have stopped. Some remain with us only in   37   . When my mother came to see my eldest daughter graduate from university, we measured her, too. It was her last visit to our home.
We haven’ t   38   the new kitchen color plan yet, but one thing is certain: whatever color we choose, the   39   of the kitchen door will still remain    40  , with lots of names and dates in various colors.

D． changeable

D． accompanied

C． schoolbags

A．information	B． handwriting
C．character	D． status

B．contributing

A．connected with	B．agreed to
C．decided on	D．relied on

填空题

用所给单词的适当形式填空

1. Please stop (talk) and listen to me.

2. Anna likes (sing) English songs.

3. Mike (be) of medium build, and (have) long hair.

4. Xu Qian loves (tell) jokes.

5. Many (person) are in blue clothes at the party.