玲玲对贝贝说：“时光如流水，一去不复返，珍惜时光就是珍惜生命!”，贝贝说：“这话道理是对的，但如果不考虑生命，只看时间，可以回到过去。”只要（    ）

    A motto is a sentence or a phrase which can inspire us especially when we are ____ (face) with difficulties. Many of us use well-know ____ (say) as mottos, such as “Where there is a will, there is a way.” Or “nothing is difficult if you put your heat into it.”, and so on. My motto is “God helps those who help____ Sometimes I am lazy ____ don't want to make efforts to work hard, but the moment I think of my motto I will get____(energy) again and devote myself to what I am doing. I write my motto ____ I can see it easily. Every time I fail in my exam and begin to lose heart, the sight of my motto inspires me ____ much confidence. My motto also makes me become an ____ (dependent) person. That is to say, I won't rely on others ____ (easy). My friends, what is your motto? If you still haven't got a motto, please choose ____ because a motto can have a great effect on you.

在下列地点中，一年中昼夜变化幅度最小的是（　）

如图所示，质量为m的物体有细绳拴住放在水平粗糙的传送带上，物体与传送带间的动摩擦因数为μ，当传送带分别以v₁，v₂的速度做逆时针运动时（v₁＜v₂），绳中的拉力分别为F₁，F₂，则下列说法正确的是（   ）