题目

将切片标木放置在对好光的显微镜载物台上．使被观察的标本正对通光孔．切片两端用压片夹压住，下一步将要进行的操作是（ ） A . 从侧面看着物镜，转动粗焦螺旋，使镜筒慢慢下降，直至物镜前端接近切片为止 B . 左眼看着目镜，转动粗准焦螺旋，使镜筒慢慢下降，直至看到较清晰的物像为止 C . 单眼看着目镜，上下转动粗准焦螺旋，直至看到较清晰的物像为止 D . 用眼注视目镜，反向转动粗准焦螺旋，直至看清物像为止(a) 根据对话内容，将方框内符合对话情境的句子写在对话的空白处，使对话恢复完整。选项中有两项是多余的。A ： Hi,Simon. Would you like to hang out with me tonight?B： 76. But I have to go over my lessons.A: What a pity! 77. B： Yes,we will have final exams this week.A： 78. B: I hope so!Thank you. But I'm a little worried.A： Worried? I know you always study well.B: But I haven’t studied science for a week.A： 79. B ： Because my science teacher is ill in hospital.A： 80. How is she now? Does she getbetter?B： Yes. My classmates and I went to see her yesterday afternoon. She will come back to school next week.Why?Don’t worry.Yes,I'd love to.I hope you’ll get good grades.Nothing serious.Fm sorry to hear that.Will you have exams this week?