题干

研究者将大白鼠置于冰水中,以探究冰水对大白鼠生理功能的影响.

(1)大白鼠刚放入冰水中时出现战栗的现象,该反射的发生____ (填“需要”或“不需要”)大脑皮层的参与,属于____ (填“条件”或“非条件”)反射.

(2)冰水刺激大白鼠皮肤____ 产生兴奋,沿反射弧____ (填“单向”或“双向”)传导到骨骼肌引起战栗.

(3)冰水刺激还能引起____ (填激素名称)分泌增加,使代谢加快,以增加产热,产生热量的是____ (生理活动).

(4)由此可见,大白鼠体温调节的方式是____ .

(5)如图是在实验过程中,测得的兴奋传导时神经纤维上某点的膜电位变化示意图,该图中表示静息电位的是____ 点,B点过程的形成原因是____ ,C点表示____ 

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阅读理解

    What's your dream vacation? Watching wildlife in Kenya? Boating down the Amazon? Sunbathing in Malaysia? New chances are opening up all the time to explore the world.So we visit travel agents, compare packages and prices, and pay our money.

    We know what our vacation costs us.But do we know what it might cost someone else?It's true that many poorer countries now depend on tourism for foreign income.Unfortunately,though.tourism often harms the local people more than it helps them

    It might cost their homes and lands.In Myanmar.5.200 people were forced to leave their homes among the pagodas(佛塔)in Bagan so that tourists could visit the pagodas.

    Tourism might also cost the local people their livelihood(生计)and dignity(尊严).Local workers often find only jobs with slim salaries in the tourist industry.And most of the profits(利润)do not help the local economy. Instead,profits return to the tour operators in wealthier countries,When the Maasai people in Tanzania were driven(驱赶)from their lands,some moved to city slums.Others now make a little money selling souvenirs or posing(摆姿势)for photos.

    Problems like these were observed more than 20 years ago.But now some non-government organizations,tour operators and local governments are working together to begin correcting them.Tourists,too,are putting on the pressure.

    The result is responsible tourism,or ethical tourism.Ethical tourism has people at its heart.New international agreements and codes of conduct(行为准则)can help protect the people's lands homes,economies and cultures.The beginnings are small,though,and the problems are complex.

    But take heart. The good news is that everyone,including us,can play a part to help the local people in the places we visit Tour operators and companies can help by making sure that local people work in good conditions and earn reasonable wages.

    They can make it a point to use only locally owned hotel restaurants and guide services.They can share profits fairly to help the local economy And they can involve the local people in planning and managing tourism.

    What can tourists do? First, we can ask tour companies to provide information about the conditions of local citizens.We can then make our choices and tell them why. And while we're abroad, we can: Buy local foods and products, not imported ones.

    Pay a fair price for goods and services and not bargain for the cheapest price.

    Avoid flaunting wealth.

    Ask before talking photographs of people.They are not just part of the landscape!

    Let's enjoy our vacation and make sure others do,too.