【单选题】
The safety of ships at sea does not depend only on the arrangements made in the ships themselves.Dangerous coasts and rocks may be seen in the daytime, {{U}} (51) {{/U}}they are a threat to safe navigation at night. Lighthouses are therefore erected at such places to{{U}} (52) {{/U}}sailors of the danger. Modern lighthouses are put up at all dangerous places near the courses{{U}} (53) {{/U}}by ships. On some rocky coasts several lighthouses may be built not far from each other, and{{U}} (54) {{/U}}the sailors on a ship may know which is which, they have{{U}} (55) {{/U}}arrangements of lights. One lighthouse will give a single flash at regular{{U}} (56) {{/U}}, another may give two flashes; a third may give two followed by one; and so on. {{U}} (57) {{/U}}watching the lights the navigator is able to decide exactly where he is, and he can set his{{U}} (58) {{/U}}with confidence. In the approaches to some ports two continuous lights are set up, one above{{U}} (59) {{/U}}but some distance behind; when they appear from the sea one above the other, the ship is on the right course; but if they do not, the captain knows that he is{{U}} (60) {{/U}}his course and likely to strike a rock or the bottom of the seA、
A．similar
B．exact
C．regular
D．different
网考网参考答案：D
网考网解析：由下文提到的不同的灯塔闪烁的次数不同可以判断D项different用在本句意思最为确切，A项similar(相似的)与下文相矛盾，B项exact“确切的；精密的”与句意不符。C项regular意为“有规律的”，这也与下文的意思不相符。
document.getElementById("warp").style.display="none";
document.getElementById("content").style.display="block";
查看试题解析出处>>
发布评论 查看全部评论