—At first I was excited, but later I got and left.
A:interesting
B:interested
C:boring
D:bored
①目镜和物镜 ____ a、调节光线强弱
②遮光镜 ____ b、放大作用
③反光镜 ____ c、反射光线
④镜筒 ____ d、连接物镜和目镜
⑤粗、细准焦螺旋 ____ e、固定玻片
⑥压片夹 ____ f、使镜筒上升或下降
如图是某城市局部街道示意图,某人想从街道口A沿街道口B,要使走的路程最短,不同的走法有( )种.