题目

小明用托盘天平测量石块的质量时，将天平放在水平桌面上，游码应移到标尺的          处。若指针位置如图甲所示，应将平衡螺母向          调节，使天平平衡。测量中，当右盘所加砝码和游码位置如图乙所示时，天平平衡，则该石块的质量为        g。 答案：左端零刻度线   左   23.4 【考点】考点7：质量和密度14.  Over the long process of evolution, animals have developed their ______ senses, which makes it possible for them to _____ their environments.A．specially; conquerB．unique; surviveC．uniquely; surviveD．special; exist