如图所示的电路中，电源两端电压保持不变，当开关S闭合时，灯L正常发光．如果将滑动变阻器的滑片P向左滑动，下列说法中正确的是（　　）

杨家将的故事流传至今已有800多年了，这些故事反映的是澶渊之盟订立之前（    ）

阅读理解

    I have five children．I'm always busy when they're awake(醒着)．That's why I try to get up before everyone else．I get up at 5：00 am．The house is quiet．I drink a cup of coffee and read books．I love that time because it's mine and I can think without interruptions(打扰)．

    —Anna

    I'm a night person．I love the night．I feel sleepy all day and then at night I wake up(醒来)!I like to dance，watch movies or talk to friends at night.I never go to sleep before 2：00a.m.

    —James

    I'm a morning person．As soon as a little light comes through the window,I wake up and start my day．I try to do important work in the morning because I know that I think best at that time．After 1：00pm，I begin to slowdown!

    —Sandra

    I love tea time．I like to have tea in late afternoon．It's a time to stop the day's activities (活动)for an hour and talk with friends．Sometimes,people visit my home-then．Sometimes，I go to a friend's house for tea．

    —Bob

根据材料内容选择最佳答案。