题干

在青藏铁路穿越可可西里的一段,专为藏羚羊设计的一条走廊——野生动物通道(如桥洞),格外引人注目。该设计目的不包括(   )高4考1资3源5网

A:防止藏羚羊出生率下降,维护种群数量的相对稳定

B:尽量保护青藏高原的原生态环境,保持物种多样性

C:降低青藏铁路对藏羚羊等高原上的大型迁徒动物的不利影响,保护其自然栖息环境

D:避免因青藏铁路的阻隔形成的地理隔离而产生生殖隔离,保持藏羚羊等物种的遗传性

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D

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  Camping in your backyard is full of fun,whatever your age.It's great for keeping us relaxed.It offers chances to check the night sky and to be noisier than usual.It lets us have friends over to stay who might not fit inside the house! Follow these instructions and you'll have a night you'll never forget! 

  Put up your tent.

Depending on the number of family members and guests,you may need

 more than one tent.Tell your friends to bring their tents if needed.Follow the instructions or check out the articles on how to put up a tent on the Internet.

    Prepare your bedding.

    You'll want your guests to be able to relax in comfort.Put something soft to lie on on the floor:A blow-up air mattress or thick comforters may work well.Fill the tent with soft toys and blankets(毯子).Have lightweight sleeping bags or cotton blankets.They are especially important if you live where the night temperatures drop greatly.

    Prepare a seating area.

    If you have a picnic table,that would work best.If not,set up a few chairs and a small table to set out drinks and food.A simple choice is to lay out a blanket in the sun,so that your friends can eat and talk.Be sure the grass isn't wet!

    Make memories.

    Plan some activities.You're camping in the backyard,so it's time to make the most of being outdoors.

    Have a camera nearby to take silly photos of you,your family members,and your friends.Take one large group shot with everyone smiling and laughing.Be sure to make copies for everyone !