皮皮学,免费搜题
登录
搜题
【简答题】
Next Stop: Planet Mars Fly me to the moon? That’s not far enough. On September 14, 2011, NASA released designs for a superrocket, the Space Launch System (SLS). This time the final destination will be Mars. The SLS is a huge, liquid-fuelled rocket. If it is fully developed, it will be the most powerful rocket ever built. Its lift capability will be much bigger than that of the space shuttle of Saturn 5, the rocket that sent the Apollo missions to the moon. NASA is planning to launch its first unmanned test flight in 2017. It is hoped that the first crew will fly in 2021 and astronauts will make it to a nearby asteroid(小行星) in 2025. NASA hopes to send the rocket and astronauts to Mars from the asteroid by the 2030s, according to the Associated Press (AP). NASA used liquid rockets to send Apollo, Gemini and Mercury into space, but later changed to solid rockets boosters(助推火箭) because they were cheaper. Tragically, however, a booster flaw(缺陷) caused the space shuttle Challenger to crash in 1986. The new project plans to return to liquid fuel. According to AP, the rockets will at first be able to carry 77 to 110 tons of payload(净载重量). Eventually they will be able to carry 143 tons into space, maybe even as many as 165 tons, NASA officials said. By comparison, the Saturn 5 booster could lift 130 tons and the space shuttle just 27 tons. However, unlike reusable shuttles, these powerful rockets are mostly one use only. New ones have to be built for every launch. This will be very costly. NASA estimates that it will cost about $3 billion (19 billion yuan) per year, or $18 billion until the first test flight in 2017. NASA hopes to make money by allowing private companies to send astronauts to the International Space Station like giant taxi services, so that the program can be “sustainable”. “This is perhaps the biggest thing for space exploration in decades,” said Senator Bill Nelson, a former astronaut. “The goal is to fly humans safely beyond low-Earth orbit(轨道) and deep into outer space where we cannot only survive, but one day also live.” 小题1:What is the outstanding feature of the SLS? A.It’s equipped with an advanced control system. B.It’s the first unmanned space shuttle in the world. C.It’s the only vehicle that can fly astronauts to the moon. D.It can send a lot more goods and passengers into space. 小题2:What is Saturn 5? A.An aircraft that had a deadly flaw and crashed in 1986. B.A series of rockets that once sent astronauts to the moon. C.An unmanned space shuttle that was once famous in the world. D.A kind of launch vehicle that will be used to carry astronauts to Mars. 小题3:NASA plans to use liquid fuel in the new project because ______ than solid rockets boosters. A.it is less costly B.it is much safer C.it can last longer D.it is more environmentally friendly 小题4:According to NASA’s schedule, it will take ______ years to fully complete the SLS program. A.about 6 B.about 10 C.less than 14 D.more than 19 小题5:It can be inferred from the passage that ______. A.the SLS program is planning to make reusable rockets B.the goal of the SLS program is to enable humans to live on the moon C.the US government may not have provided enough money for the SLS program D.NASA will use SLS as a space taxi between the Earth and Mars
拍照语音搜题,微信中搜索"皮皮学"使用
参考答案:
参考解析:
知识点:
.
..
皮皮学刷刷变学霸
举一反三
【单选题】小腿三头肌的主要功能是
A.
伸膝关节,屈踝关节
B.
伸膝关节,上提足跟
C.
屈膝关节,上提足跟
D.
屈膝关节,同时屈踝关节
【简答题】小腿三头肌的主要功能是( )。
【单选题】小腿三头肌的主要功能是( )
A.
使小腿屈和踝关节屈
B.
使小腿屈和踝关节伸
C.
使踝关节内翻
D.
使踝关节外翻
【单选题】市场经济的共同特征不包括()
A.
自主性
B.
平等性
C.
求利性
D.
科学性
E.
竞争性
【单选题】自计算机问世至今已经经历了四个时代,划分时代的主要依据是计算机的( )
A.
规模
B.
性能
C.
功能
D.
构成元件
【单选题】( )不是小腿三头肌的功能
A.
屈膝关节,上提足跟
B.
屈膝关节,背屈踝关节
C.
屈膝关节,跖屈踝关节
D.
屈膝关节,伸踝关节
【单选题】小腿三头肌的主要功能是( )
A.
伸膝关节,屈踝关节
B.
伸膝关节,上提足跟
C.
屈膝关节,上提足跟
D.
屈膝关节,同时屈踝关节
【单选题】小腿三头肌的首要功能是
A.
屈踝关节
B.
伸踝关节
C.
屈膝关节
D.
伸膝关节
【多选题】煤矿巷道掘进中,装岩时间占整个循环的50%-70%,提高其机械化水平是快速掘进的关键,机械化装岩一般有: _____________
A.
侧卸式装岩机
B.
后卸式装岩机
C.
蟹爪装岩机
D.
耙斗装岩机
【单选题】自计算机问世至今已经经历了四个时代,划分时代的主要依据是计算机的 。
A.
规模
B.
功能
C.
性能
D.
构成原件
相关题目: