一把抓由上接头和带抓齿的筒体组成。

如图18所示，水平面上有两根相距0.5m的足够长的平行金属导轨MN和PQ，它们的电阻可忽略不计，在M和P之间接有阻值为R＝3.0Ω的定值电阻.导体棒ab长l＝0.5m，其电阻为r＝1.0Ω，与导轨接触良好.整个装置处于方向竖直向上的匀强磁场中，磁感应强度B＝0.4T.现使ab以v＝10m/s的速度向右做匀速运动.

⑴ab两点电势差为多少？

⑵使ａｂ棒向右匀速的拉力F为多少？

⑶拉力的功率为多少？

死亡细胞变为嗜酸性，细胞核的超微结构消失，但细胞和组织结构轮廓仍存在，这种改变为干酪样坏死。

I arrived at my mother’s home for our Monday family dinner. The smells of food flew over from the kitchen. Mother was pulling out quilt(被子)after quilt from the boxes, proudly showing me their beauties. She was preparing for a quilt show at the Elmhurst Church. When we began to fold and put them back into the boxes, I noticed something at the bottom of one box. I pulled it out. “What is this?” I asked.

“Oh?” Mom said, “That’s Mama’s quilt.”

I spread the quilt. It looked at if a group of school children had pieced it together; irregular designs, childish pictures, a crooked line on the right.

“Grandmother made this?” I said, surprised. My grandmother was a master at making quilts. This certainly didn’t look like any of the quilts she had made.

“Yes, right before she died. I brought it home with me last year and made some changes,” she said. “I’m still working on it. See, this is what I’ve done so far.”

I looked at it more closely. She had made straight a crooked line. At the center of the quilt, she had stitched(缝) a piece of cloth with these words:  “My mother made many quilts. She didn’t get all lines straight. But I think this is beautiful. I want to see it finished. Her last quilt.”

“Ooh, this is so nice, Mom,” I said. It occurred to me that by completing my grandmother’s quilt, my mother was honoring her own mother. I realized, too, that I held in my hands a family treasure. It started with the loving hands of one woman, and continued with the loving hands of another.

小题1:Why did the author go to mother’s home?

A．To see her mother’s quilts.

B．To help prepare for a show.

C．To get together for the family dinner.

D．To discuss her grandmother’s life.小题2:The author was surprised because      .

A．the quilt looked very strange.

B．her grandmother liked the quilt.

C．the quilt was the best she had seen.

D．her mother had made some changes小题3: The underlined wood “crooked” in the passage most probably means       .

A．unfinished

B．broken

C．bent

D．unusual小题4: Which of the following would be the best title for the passage?

A．A Quilt Show

B．Mother’s Home

C．A Monday Dinner

D．Grandmother’s Quilt

未取得母婴保健技术相应合格证书，出具有关医学证明的，给予行政处罚应包括（）

A.停业整顿

B.罚款

C.没收非法所得

D.取消执业资格

E.吊销执业证书

该企业生产、经营自用房应缴纳的房产税为( )万元。

A．4.8

B．3.36

C．5.4

D．3.78