定性鉴别环烯醚萜类化合物的反应是( )A．与Dragendoff's试剂呈阳性反应

回答下列问题：

（1）图中A烧杯盛有浓氨水，B烧杯内是滴加了几滴酚酞溶液的蒸馏水．过一会儿，观察到的现象是______，本实验说明______．

（2）氨气（NH₃）在纯净氧气中燃烧，生成空气中含量最多的气体和一种常温下为液体的氧化物，该反应的化学方程式为______，其基本反应类型是______．

如图所示，质量为m、电荷量为q的带电粒子，以初速度v₀垂直射入场强为E,方向竖直向下的匀强电场中，该粒子在电场中的经历时间_____后，其即时速度的方向与初速度方向成30º角．在这过程中粒子的电势能增量为_______．

I remembered that when I was a little child, I used to look for Sunday of the week. Yes, I was so looking forward to an adventure.

Now, I still have a strong affinity for buses. I used to wonder where those gigantic (巨大的) buses finally stopped. On sunshine Sundays, that’s my adventure times. He took me to the bus stop. Time passed, while I was growing impatient, he was smiling, as he always does.

It was really not that easy to get on a bus as often as we do today. I was so worried that the bus driver would have missed us. I waved my hands so high with all my strength. I looked hopefully at him. He didn’t move at all. He was still standing. It seemed that the late and infrequent coming of the bus wasn’t any trouble to him at all.

He took my hand. We managed to find seats on the upper deck. I was so excited. Only sitting beside the windows made me happy. Looking at the rewinding buildings, streets and people through windows from a higher ground was so much fun. Then, he was sitting peacefully by me and whispered to me where the bus finally would stop. I was curious about what would be the next stop of our destination as much as what really means something to him.[]

That is me. I know now. I am all he cares. He wants me to be happy, as he always does. That’s the strong bond between father and son. Childhood, naive(天真)  and precious, you showed me the world and the way I look at the world. I am so grateful for your presence in my life. Thanks, you are so wonderful!

小题1:Who is “he” throughout the text?

A．The brother of the writer.

B．The son of the writer.

C．The father of the writer.

D．A bus driver.小题2:In the second paragraph, what is the probably meaning of “affinity”?

A．Hate.

B．Disappointment.

C．Liking.

D．Confusion.小题3:Where does this text probably come from?

A．A bus guide.

B．A student’s diary.

C．An adventure story.

D．A transportation report.

分析机床数控系统的组成和工作过程。

水系和干流的概念