昆虫口器着生的位置有哪几种?
参考答案:
前口式、后口式、下口式。
如图所示,竖直墙面与水平地面均光滑且绝缘,两个带有同种电荷的小球A、B分别处于竖直墙面和水平地面,且处于同一竖直平面内,若用图示方向的水平推力F作用于小球B,则两球静止于图示位置.如果将小球向左推动少许,并待两球重新达到平衡时,跟原来的状态相比( )
A.推力F将增大
B.竖直墙面对小球A的推力变大
C.地面对小球B的支持力不变
D.两小球之间的距离变大
According to cognitive theories of emotion,______anger occurs when______individuals believe that they have been harmed and that______harm was both avoidable and undeserveD.
A.a.../...the B.an.../...a C./.../...the D./.../...a