Silica-alumina catalysts
[化] 硅铝催化剂
🧩 词语组成解析
silica
['silikə]
n. 硅石，二氧化硅;硅氧;
n. 矾土\\n[化] 矾土; 氧化铝
n. <化>催化剂( catalyst的复数形式 ); 触媒; 促进因素; 有感染力的人
🗣️ 情景例句
You have to expect the unexpected in Shanghai.
在上海，你总会有意想不到的收获。
I'll call the roll before class.
课前我要点名。
Yes, and we must stop people walking on this floor until it's firm. It may be necessary to put up a notice saying Keep off. Another thing, we' ll have to drill a hole in the wall for the electric wires.
是的，因此在地板牢固前，我们必须防止人们从地板上行走。可能还需要竖一个布告牌，写上“不得践踏”。还有，我们必须在墙上钻一个电线孔。