阅读下面的短文,请根据短文后的要求答题(请泣意问题后的字数要求)

As in the field of space travel, so in the undersea exploration (探险) new technologies continue to appear, They         with each other-as well as some important differences

Manned submersibles (潜水器),like spaceships, must miantain living conditions in an unnatural environment. But while a spaceship must simply be scaled(密封)against the vacuum (真空) of space, a submersible must be able to bear extreme pressure if it is not to brisk up in deep water

In exploring space, unmanned vehicles were employed before astronauts, in the undersea exploration, on the other hand, men paved the way, and only recently have unmanned remote operated vehicles (ROVs) been put to use

One reason for this is that communicating with vehicles in orbit is much easier than talking to those underwater, A vacuum is an ideal medium for radio communications, but underwater, communications are limited to much slower sound waves ,Thus, most undersea vehicles, particularly ROVs , operate at the end of long ropes

For a similar reason, knowing where you are undresea is much more difficult than in space, A spaceship’s position can be located by following its radio signal, or by using telescopes and radars, For spaceship’s position can be located by following its radio signal, or by using telescopes and radars, For an undersea vehicle, however, a special network of sonar(声纳) devices must be laid out in advance on the ocean floor in the area of a dive to locate the vehicle’s position

Though undersea exploration is more challenging than outer space in a number of respects , it has a distinct advantage: Going to the ocean depths doesn’t require the power necessary to escape Earth’s gravity Thus it remains far less expensive

  76.What is the best title for this passage‘’(within 10 words)

                                                                                

  77.Which sentence in the passage is the closest in meaning to the following one?

    Similarly, it is more difficult to know where you are underwater

―――――――――――――――――――――――――――――――――――――――

  78.What do you think of the undersea exploration? Why? (Within 20 words)

―――――――――――――――――――――――――――――――――――――――

  79.Fill in the blank in the first paragraph with a proper phrase(within 10 words)

    ―――――――――――――――――――――――――――――――――――――――

  80.Translate the underlined sentence in the last paragraph into Chinese

―――――――――――――――――――――――――――――――――――――――

 0  31236  31244  31250  31254  31260  31262  31266  31272  31274  31280  31286  31290  31292  31296  31302  31304  31310  31314  31316  31320  31322  31326  31328  31330  31331  31332  31334  31335  31336  31338  31340  31344  31346  31350  31352  31356  31362  31364  31370  31374  31376  31380  31386  31392  31394  31400  31404  31406  31412  31416  31422  31430  151629 

违法和不良信息举报电话:027-86699610 举报邮箱:58377363@163.com

精英家教网