如图为显微镜观察某标本细胞的两个视野图,从甲图变为乙图的第一步操作是( )
A:换成高倍物镜
B:调节光圈
C:调节细准焦螺旋
D:装片向左移动
选择加下划线字的意思
—Have you ever ______ Jin Yong?
—Of course, a very famous writer, and he once studied in Quzhou.
下列各式中与12是同类二次根式的是( )
What about there by bus, Tom?