【简答题】连接上海市区到浦东国际机场的磁悬浮轨道全长约为30km,列车走完全程包含启动加速、匀速运行、制动减速三个阶段.已知磁悬浮列车从启动加速到稳定匀速动行共需200秒,在这段时间内记录下下列数据: 时间t(秒) 0 50 100 150 200 速度υ(米/秒) 0 30 60 90 120 路程x(米) 0 750 3000 6750 12000 (1)请你在一次函数、二次函数和反比例函数中选择合适的...
【简答题】我国青海省玉树地区发生强烈地震以后,国家立即启动救灾预案,积极展开向灾区运送救灾物资和对伤员的救治工作.已知西宁机场和玉树机场相距800千米,甲、乙两机沿同一航线各自从西宁、玉树出发,相向而行.如图,线段AB、CD分别表示甲、乙两机离玉树机场的距离S(百千米)和所用去的时间t(小时)之间的函数关系的图象(注:为了方便计算,将平面直角坐标系中距离S的单位定为(百千米)).观察图象回答下列问题: (1...
【单选题】Even though she herself has never had such an experience, it's______ she can recognize from what has happened to her good friend.
【单选题】听力原文:What has happened to the woman? (15)
A.
She has had a car accident.
B.
She has had trouble with the car.
C.
She has been hurt in a crash.
【单选题】This is an old photo of my aunt’s when she had ___ , and she now she has ____.
A.
short hair; gray hairs
B.
short hairs; gray hair
D.
short hairs; gray hairs
【简答题】我国青海省玉树地区发生强烈地震以后,国家立即启动救灾预案,积极展开灾区运送救灾物资和对伤员的救治工作.已知西宁机场和玉树机场相距800千米, 乙两机沿同一航线各自从西宁、玉树出发,相向而行.如图,线段AB、CD分别表示甲、乙 两机离玉树机场的距离S(百千米)和所用去的时间t(小时)之间的函数关系的图象(注: 为了方便计算,将平面直角坐标系中距离S的单位定为(百千米)).观察图象回答下列问题: (1...
【判断题】强壮的酵母细胞壁厚,细胞衰老时细胞壁逐渐变薄。