【简答题】阅读理解。 Surely, it's good to get along with your teacher because it makes the time you spend in the classroom more pleasant. But really, there's one important reason why you should get along with your t...
【简答题】There are many signs in public places. You should know their meanings(意思). Or you will get into trouble(麻烦). For example, you will see the following(以下的) two signs on the wall in a hospital: You may s...
【简答题】To: William Smith, Manager From: Lucy, Wu Date: June 6th, 2019 Subject: Sick leave Mr. William, It's very 1 that I have a severe headache today. I think I should go to 2 to see a doctor. So I want to ...
【简答题】硫化氢(H 2 S)是一种具有臭鸡蛋气味的无色气体,有剧毒;存在于多种生产过程以及自然界中。在人体的很多生理过程中也起着重要作用。 资料:① H 2 S可溶于水(约1:2),其水溶液为二元弱酸。 ② H 2 S可与许多金属离子反应生成沉淀。 ③ H 2 S在空气中燃烧,火焰呈淡蓝色。 (1)某化学小组设计了制取H 2 S并验证其性质的实验,如下图所示。A中是CuSO 4 溶液,B中放有湿润的蓝色石...