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【简答题】

Five million people visit Grand Canyon in the US every year. For the purpose of helping protect Grand Canyon for your fellow visitors and future generations, please follow the guidelines below.
Camping
To protect the park, camping is allowed only within permitted campgrounds. Permits are required for overnight camping at the North Rim. Advance booking can be received by mail. Please write: Information Center, P.O. Box 129, Grand Canyon, AZ 86023.
Fires
Because of the extreme fire er, campfires are not allowed except at Mather and Desert View campgrounds. Collection of firewood is not allowed either.
Hiking(远足)
Please stay on permitted paths. Otherwise you may destroy desert plants. Pack out what you pack in, so you leave no signs of your visit. It is important to keep in mind that you are in a national park where wildlife exists.
Weather
The weather at Grand Canyon can change very quickly. With so much rock, lightning(闪电) causes a particular er during sudden summer storms. These storms also frequently bring floods inside valleys, a er to hikers. Watch the skies and check daily weather reports.
Wild life
Do not feed park wildlife. There have been a few cases at Grand Canyon National Park where deer(鹿) were purposely shot because they ate plastic bags that left them sick and weak. Hungry deer can be a er and have kicked and bitten visitors at Grand Canyon. Some other animals Will also beg and bite. For your own safety and the well-being of the animals, please do not feed wildlife, no matter how gentle they may appear.
Guidelines
Camping:1. (47) campgrounds in advance.
2.allowed only within permitted campgrounds.
Fires:1.not allowed except at Mather and Desert View campgrounds.
2.not allowed to (48) firewood.
Hiking:1.stay on permitted paths.
2. (49) everything you bring in.
Weather:Watch the skies and50) daily weather reports.
Wildlife: Don’t (51) Bark wildlife.
CampingFiresHikingWeatherWild lifeGuidelinesCamping:Fires:Hiking:Weather:Wildlife:

题目标签:闪电
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参考答案:
参考解析:
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刷刷题刷刷变学霸
举一反三

【单选题】闪电是( )。

A.
自然环境中的强放电现象
B.
雷公电母释放的
C.
上天对坏人的惩罚

【单选题】打雷时,先看到闪电后听到雷声的原因是[ ]

A.
闪电先发生,打雷后发生
B.
打雷先发生,闪电后发生
C.
闪电和雷声同时发生,但光速比声速大得多
D.
发生闪电的地方离地面近

【单选题】雷电时是先看闪电,还是先听雷声?

A.
先看见闪电
B.
先听到雷声
C.
闪电与雷声同时

【单选题】雷鸣闪电时,可以从开着的收音机里听到“咯咯”的响声,这是因为()

A.
收音机出现故障
B.
空气潮湿的缘故
C.
雷声传到了收音机中
D.
收音机收到了云层间传来的电磁波

【多选题】现有研究闪电的方法有()。

A.
测量闪电通道的电流
B.
电磁场
C.
声信号
D.
发射光谱
相关题目:
【单选题】闪电是( )。
A.
自然环境中的强放电现象
B.
雷公电母释放的
C.
上天对坏人的惩罚
【单选题】打雷时,先看到闪电后听到雷声的原因是[ ]
A.
闪电先发生,打雷后发生
B.
打雷先发生,闪电后发生
C.
闪电和雷声同时发生,但光速比声速大得多
D.
发生闪电的地方离地面近
【单选题】雷电时是先看闪电,还是先听雷声?
A.
先看见闪电
B.
先听到雷声
C.
闪电与雷声同时
【单选题】雷鸣闪电时,可以从开着的收音机里听到“咯咯”的响声,这是因为()
A.
收音机出现故障
B.
空气潮湿的缘故
C.
雷声传到了收音机中
D.
收音机收到了云层间传来的电磁波
【多选题】现有研究闪电的方法有()。
A.
测量闪电通道的电流
B.
电磁场
C.
声信号
D.
发射光谱
【单选题】绝缘子的击穿电压至少等于干闪电压的()。
A.
(A)0.5倍
B.
(B)1.5倍
C.
(C)2.5
D.
(D)3.5倍