问题 问答题 简答题

简述等高线的特性?

答案

参考答案:

(1)在同一条等高线上的各点,其高程相等。

(2)是一条闭合曲线,不会中断,由于一幅图所示的范围有限,如在本图幅内不闭合,则在相邻图幅内仍最终自成闭合。

(3)一条等高线不能分叉两条;不同高程的等高线,不能相交或者合并成一条;在悬崖处的等高线虽然相交,但必须有两个交点。

(4)等高线愈密则表示坡度愈陡,等高线愈稀表示坡度愈缓,等高线之间平距相等则表示坡度相等。

(5)经过河流的等高线不能直接跨越而过,应该在接近河岸时,渐渐折向上游,直到与河底等高处才能越河而过,然后再折向下游渐渐离开河岸。

(6)等高线通过山脊时,与山脊线成正交,并凸向低处;通过山谷线时,则应与山谷线成正交,并凸向高处。

单项选择题

阅读下面短文,从短文后各题所给的四个选项(A、B、C 和 D)中,选出可以填入空白处的最佳选项,并在答题卡上将该项涂黑。

                                    A Heroic Driver

Larry works with Transport Drivers. Inc. One morning in 2009. Larry was  41

along 165 north after delivering to one of his    42   . suddenly, he saw a car with its bright lights on.    43    he got closer, he found 44    vehicle upside down on the road. One more look and he noticed    45    shooting out from under the    46    vehicle. Larry pulled over, set the brake and    47   the fire extinguisher (灭火器). Two good bursts from the extinguisher and the fire was put out.

The man who had his bright lights on    48    and told Larry he had    49    an emergency call. They    50    heard a woman’s voice coming from the wrecked (毁坏的) vehicle.    51   the vehicle, they saw that a woman was trying to get out of the broken window. They told her to stay    52    until the emergency personnel arrived,    53    she thought the car was going to    54   . Larry told her that he had already put out the fire and she should not move    55    she injured her neck.

Once fire and emergency people arrive, Larry and the other man    56    and let them go to work. Then, Larry asked the    57    if he was needed or    58    to go. They let him and the other man go.

One thing is    59   —Larry went above and beyond the call of duty by getting so close to the burning vehicle! His    60    most likely saved the woman’s life.

59()

A.for certain

B.for consideration

C.reported

D.checked

判断题