expansion bolt（膨胀螺栓）是什么意思？音标发音+图解场景

膨胀螺栓 /ɛkspˈanʃən ˈbəʊlt/ n

English: expansion bolt · 膨胀螺栓

释义：Part composed of a bolt in a sheath that bends when the bolt is inserted, then flattens out against the inside of the wall. washers

这个词出现在以下图解场景（1）