题目

______the fog, we should have reached our school in time. A. In case of    B. Due to     C. But for   D. In spite of 答案：C16．许多实验都要借助显微镜观察．下列结构或器官必须在显微镜下才能更好地观察的是（　　）A．小肠绒毛和皱襞B．植物的根毛C．叶片的气孔D．河蚌的斧足