将JK触发器的J，K端连接起来（如图所示），若脉冲信号、置位端、复位端和数据X端信号

PNH是一种造血干细胞基因突变引起的溶血性疾病，以____为主要特征，多为慢性____溶血。

阅读理解。

      One afternoon, my son came home from school and asked me, "Are all people the same even if their

skin color is different?" I thought for a moment, then I said, "I'll explain. Let's go to a fruit store first. I

have something interesting to show you."

     At the store, I told him that we needed to buy apples. And we bought some red apples, green apples and

yellow apples.

     After we got home, I told Adam, "It's time to answer your question." I put one of each type of apple on

the table: first a red apple, followed by a green apple and then a yellow apple. Then I looked at Adam, who

was sitting on the other side of the table.

     "Adam, people are just like apples. They come in different colors, shapes and sizes. See, some may not

even look as delicious as others." As I was talking, Adam was examining each one carefully.

     Then, I took each of the apples and peeled them, placing them back on the table, but in a different place.

     "OK, Adam, tell me which one is the red apple, the green apple and the yellow apple."

      He said, "I can't tell. They all look the same now."

      "Take a bite (一口) of each one. See if that helps you tell which one is which."

     He took big bites, and then a huge smile came across his face. "People are just like apples! They are all

different, but if you take off the outside, they're pretty much the same on the inside."

     "Right," I agreed. "Just like everyone has their own features but they are nearly the same."

     He completely got it. I didn't need to say or do anything else.

     Now, when I eat an apple, it tastes a little sweeter than before. What perfect fruit it is!

1. I took Adam to buy apples for ________.

A. supper

B. his question

C. a party

D. a present

2. As soon as we got home, I put ________ on the table.

A. all the apples

B. three apples of different colors

C. three red apples

D. three peeled apples

3. After Adam took big bites, he found they ________. 

A. looked the same

B. tasted good

C. tasted the same

D. weren't delicious

4. In the end, Adam understood that ________.

A. people are much the same even if their skin color is different

B. people are different if their skin color is different

C. the apples look the same after they are peeled

D. apples of different colors taste different

5. I feel that apples taste a little sweeter than before because ________.

A. they are delicious enough

B. they are perfect fruit for thinking

C. they are safe fruit

D. my son falls in love with them

最终决定农业生产的类型和规模的社会经济因素是（  ）

A．气候

B．地形

C．交通

D．市场

根据列车制动力的获取方式不同，可分为（）与非粘着制动。

船上的救生衣通常存放在旅客和船员住舱的（），以方便人员使用。

A.书柜内

B.衣柜内

C.保险箱