【单选题】当观察者向着波源运动时,观察者接收到波的频率升高,其原因是( )。
B.
观察者单位时间内接收到的完整波的数目增加,相当于波速增大,根据ν=u/λ,所以引起频率升高
【判断题】英格兰式拍卖又被称为维克里拍卖,能够充分激励竞买人按照自己对物品的估价来出价。
【简答题】资本主义生产过程是劳动过程和价值形成过程的统一。
【单选题】以下有关软骨细胞结构特点的描述中,错误的是
B.
深层的细胞逐渐增大,并不断分裂、增殖,形成同源细胞群
C.
浅层的软骨细胞呈扁平椭圆形,体积较小,处于成熟阶段
D.
电镜下胞质可见内含丰富的粗面内质网和发达的高尔基复合体
【单选题】Which of the following represents the emergency signal for fire aboard ship?
A.
More than six short blasts and one long blast on the whistle
B.
Continuous blast of the ships whistle for a period of not less than 10 seconds supplemented by the same signal on the general alarm
C.
Three short blasts of the whistle supplemented by the same signal on the general alarm
D.
More than six short blasts and one long blast on the whistle supplemented by the same signal on the general alarm
【判断题】英格兰式拍卖又被称为维克里拍卖,能够充分激励竞买人按照自己对物品的估价来出价。
【简答题】Listen to the second part of the speech and fill in the blanks of the sentence below with two or three words. Getting to know the following words first might be helpful. pathogen /ˈpæθədʒən/ n. 病原体 v...