——What _______ if you don't finish your work on time?
——Mrs. Brown will be very angry.
A:happens
B: is happened
C:happened
D:will happen
下面是光学显微镜观察植物叶表皮气孔时的几个操作步骤。要把显微镜视野下的图像从下图中的甲转为乙,规范的操作步骤是①移动载玻片 ②调节光圈和反光镜③转动转换器 ④转动细准焦螺旋⑤转动粗准焦螺旋
下列说法中正确的是( )