下载APP
举一反三
【单选题】瞄准水准尺的步骤为
A.
目镜对光-初步照准-物镜对光-消除视差;物镜对光-初步照准-目镜对光-消除视差
B.
初步照准-物镜对光-目镜对光-消除视差
C.
消除视差-初步照准-物镜对光-目镜对光
【多选题】下列关于瞄准的叙述，正确的有( )。
A.
测角瞄准用的标志一般是标杆、测杆或用三根竹竿悬吊垂球或觇牌
B.
测角瞄准时，首先应转目镜螺旋，使十字丝清晰
C.
瞄准目标一定要注意“先精瞄、后粗瞄的原则”
D.
精瞄准要转动微动螺旋，为提高瞄准的精度转动微动螺旋，最后以旋进结束
E.
瞄准目标时要注意消除视差，眼睛的视线应左右移动观察目标的像与十字丝是否存在错动现象
【单选题】Genetically-modified foodstuffs are here to stay. That's not to say that food produced by conventional agriculture will disappear, but simply that food-buying patterns will polarize: there will be a n...
A.
Because they will be cheaper than conventional foodstuffs.
B.
Because they will remove people's worries about taking many chemicals.
C.
Because it will be more convenient for people to get them.
D.
Because conventional foodstuffs will not be available in the future.