I always wondered how people would react if I tried to approach a total stranger for help in a busy place like a street corner or a mall. I have always 1 a stranger who tried to catch my2 in a busy place.

    Yesterday I was in a busy shopping mall buying a large piece of luggage because I just had the 3 to do it after many days of planning. After the 4 I picked up my phone from my pocket to call my driver waiting in the parking lot but my phone was 5.

    Then I requested the shop assistant who had 6 sold me the merchandise (which was not cheap), if she could ring my driver for me. She 7 that it was the shop policy that they cannot use 8 while working in the shop.

    After I got out of the shop onto the busy street, I 9 a young mother with her two kids to make the same 10As soon as I said “Excuse me, madam!” she grabbed her kids and ran. I 11 a kidnapper(绑匪).

    I stood there wondering how many times I had 12 to strangers like the young13 I stood there in the 14 street with people rushing by, looking at their faces to see if there was a sign of 15 on their face.

I saw a man pretty shabbily dressed compared to me who 16 to notice me. I just stopped him and made my request. He17called my driver and waited till my car came to make sure I was picked up, turned around 18 I could thank him adequately and was gone.

    I was 19 by kindness and hope I will do20 to strangers who try to catch my attention from now on.

欧洲地形以____为主，山地主要分布在南北两侧。南部为阿尔卑斯山脉，北部为斯堪的纳维亚山脉。

阅读下文，完成后面练习题。

　　淮阴侯韩信者，淮阴人也。始为布衣时，贫，无行，不得推择为吏，又不能治生商贾，常从人寄食饮，人多厌之者。常数从其下乡南昌亭长寄食，数月，亭长妻患之，乃晨炊蓐食。食时，信往，不为具食，信亦知其意，怒，竟绝去。

　　信钓于城下，诸母漂，有一母见信饥，饭信，竟漂数十日。信喜，谓漂母曰：“吾必有以重报母。”母怒曰：“大丈夫不能自食，吾哀王孙而进食，岂望报乎！”

　　淮阴屠中少年有侮信者，曰：“若虽长大，好带刀剑，中情怯耳。”众辱之曰：“信，能死，刺我；不能死，出我胯下。”于是信孰视之，俛出胯下，蒲伏，一市人皆笑信，以为怯。

　　                                                  （节选自《淮阴侯列传》）

有一次上课时，小明觉得很闷，呼吸不畅。他认为可能是教室里二氧化碳的含量较高的缘故，应该用澄清石灰水来检验一下。就“可能是教室里二氧化碳的含量较高”而言，属于科学探究中的（   ）