标本片上的某一物象，第一次看到后如何再次找到它？
参考答案：
要做到这一点，首先取决于显微镜的好坏，若显微镜上的推动器带有纵横标尺，很容易做到这一点。首先记住标本片放到推动器上的方向，然后记下观察某一物体时推动器上的纵横标尺的数字。如纵3，横4。
当标本片拿下来后，若要重复观察原来的物象，只要按原方向将标本片荚在推动器上，将推动器推动到第一次观察该物体的纵，横标尺数字纵3，横4，即可看到第一次观察过的物体。
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 John loved playing basketball after school. John's parents were anxious about their son because he __1__ half of his spare time playing basketball, even though he would soon __2__ the college entrance exam (高考). Many evenings, John returned home__3__ at the beginning of the new term. His parents told him to concentrate more __4__ his studies, but their words went in one __5__ and out the other. His parents were so angry that they __6__ his basketball. From that day on, John returned home on time but locked __7__ in his room. At first, his parents dreamt their son could study hard to enter a top university. But __8__ news shattered (破灭) their dream. John's pre-exam test scores were __9__. One night, John's mother looked into his room and __10__ him reading a basketball magazine. So John's parents discussed the matter. They __11__ to make a deal (约定) with John. If John scored high marks in the following tests, he could get his ball back and __12__ once again; if he failed, they would keep the ball __13__ he improved. John __14__ reading his magazines. He started working hard. He started getting high marks and got his __15__ back. The ball stayed with John until he entered a top university. | ||||
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