题干

X、Y、Z、W都是短周期元素,核电荷数依次增大。X和Z同主族,Y、Z、W同周期,Y的原子半径是所处周期中最大的, W的最高价氧化物所对应的水化物是强酸,X与W的核电荷数之比为3∶8。据此判断下列说法正确的是

A:Y是第三周期ⅦA族元素

B:Z一定是金属元素

C:非金属性:W﹥X

D:Y与W的最高正价之和为8

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答案(点此获取答案解析)

C

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Big City Bus Driver

    When I was 20, I went to stay with a friend for two weeks in Vancouver. My friend worked during the day, so I decided to go 1 on my own. I knew where I was and where I wanted to go, the Vancouver Aquarium (温哥华水族馆). It sounded 2.

    But soon I was completed 3 I boarded a bus, figuring it must do a circle, right? I rode a good half hour before becoming impatient and then got 4 I walked quite a while, up and down various blocks, but had no idea where I was.

    I've lived in a tiny town all my life, rarely leaving it. Being a “small town girl”, I admit I'm fairly 5about city life. People at home always told me city people were cold and unconcerned about others, so I was afraid to 6to anyone.

    I got on another bus, and then another again. Finally, after hours, I decided to get on ONE bus, and stay on 7 I recognized something. I rode over half an hour. Nothing ever seemed 8 When I became the only passenger on the bus, I began to get 9 I had no cellphone, and didn't even10 my friend's office telephone number.

    As I was about to give up and leave the bus, the driver asked11 I wanted to go. I told him the aquarium, and he laughed, saying his bus wouldn't go anywhere near. I12 back in my seat, really afraid and upset. He asked where I was from, and I told him what had happened and now I just wanted to go back to my friend's place.

    13, the driver pulled the bus over and called me to the front. He gave me detailed 14 as to which buses to take, and how to understand the bus system. He 15 printed the bus tickets I needed from his machine.

    I was shocked. He spent a good twenty minutes 16 me, telling me everything I needed to know, before giving me the tickets. I thanked him repeatedly, and asked him how much I 17 for the tickets. “Nothing. Just get yourself to your friend's home.”

    Thanks to his 18 I was able to make my way back to my friend's house. I don't know what I would have done if that driver had not taken the 19 to help me. What people had told me was not true. City people 20 just like the driver. I never did learn his name, but I'll always remember him.