Is this a cat?
A:No, it's a cat.
B:No, it's a dog.
如图所示,杠杆在力F1、F2作用下处于平衡状态,L1为F1的力臂,请在图中作出力Fl;若L1=60cm,OA=40cm,F2=120N,则F1的大小为 ____N.
Linda's aunt and uncle _______ workers.