【单选题】Laser-dopple radar is especially valuable in space missions because it ______ .
A.
is one thousand times more precise than microwave radar
B.
provides precise measures of the velocity of space vehicles
C.
is a new system of radar
D.
can measure the movement of a spaceship less accurately than a microwave radar
【单选题】Laser-doppler radar is especially valuable in space missions because ______.
A.
it is one thousand times more precise than microwave radar
B.
it provides precise measures of the velocity of space vehicles
C.
it is a new system of radar
D.
it can measure the movement of a spaceship less accurately than a microwave radar
【多选题】运动就是物体“不断地放弃一个位置,又取得另一个位置”,这段话的意蕴是
【单选题】One of the missions that Franklin carried out in France is to persuade the French government to give financial aid to the American colonies.
【单选题】在雷雨天不要走近高压电杆、铁塔、避雷针,远离至少()以外。
【单选题】One of the missions of the Orbiting Carbon Observatory is
A.
to observe the formation of CO2.
B.
to collect CO2 samples from space.
C.
to do CO2 experiments in space.
D.
to locate the key places of CO2 emission.
【判断题】上下影线等长的十字星,称为转机线,常在反转点出现。