問題詳情

二、金屬切削加工時在切削刀具、被切削工件與切屑上會產生大量的熱,試說明這些熱產生的主要來源。(20 分)

參考答案

答案:B
難度:簡單0.784615
統計:A(10),B(408),C(26),D(76),E(0)

用户評論

Tina Chien】評論

hatch 孵出

不要讚.會被販售】評論

 It begins to eat and grow. Later, the caterpillar gets rid of its skin and becomes a pupa. When the adult butterfly has formed, it is ready to come out. Some butterflies live for as long as eighteen months. But some live for only two weeks. During that time, most butterflies _____9_____ their mates. The female butterflies will lay eggs, and the life cycle will begin again.

olra】評論

First, a female butterfly lays eggs. Then a caterpillar hatches from an egg.→首先,雌性蝴蝶產卵。 然後,一隻毛毛蟲從一個蛋孵出來。