A:棉花和花生
B:大豆和甜菜
C:棉花和油菜
D:油菜和甘蔗
Bob: What do you usually____ (do) on Sunday, Ann?
Ann: I usually____(go) to the library with my sister, Betty. But sometimes my grandfather____(go) with me. He____(like) reading very much.
为了测定乙醇的结构式,利用乙醇和钠的反应,设计如图1装置进行实验,在烧瓶中放入足量的钠,从分液漏斗中缓缓滴入一定量的乙醇,通过测量量筒中水的体积,就可知反应生成的氢气的体积.