We need to _____ after eating to have good teeth.
A:take a walk
B:brush our teeth
C:get dressed
D:o our homework
如图所示,用水平力F拉着长木板A在水平地面上做匀速直线运动,木块B始终静止不动,若不计绳和弹簧测力计重,下列说法中正确的是( )
lake
下列动物中不能帮助植物传粉的是( )