n.毛边书
名词bolt的复数形式.
He can drive a car but he doesn't know anything about the nuts and bolts of the engine. 他会开汽车，但他对汽车发动机的结构一窍不通。
Bolts are making in this shop. 这个车间正在制造螺钉。
These nuts and bolts hold the wheels on. 这些螺帽和螺栓把轮子固定住了。
The gate bolts on the inside. 这大门是从里面闩上的。
