牙体缺损最常见的原因是（）。 A.龋病 B.夜磨牙 C.牙外伤 D.楔状缺损 E.发

甲公司持有一张由乙公司出票、经丙公司背书转让获得的银行承兑汇票。在该汇票到期后，甲公司向承兑银行提示付款时遭到拒绝，承兑银行拒付的理由是：该汇票上银行的签章是伪造的，该银行并未承兑过这张汇票。甲公司于是向丙、乙公司进行追索，丙公司声称该汇票是乙公司某业务员给付的，并经乙公司背书转让取得，伪造签章的责任应由乙公司承担，与其无关。乙公司则答复说，该汇票出票及背书转让都是其一业务员伪造公司签章所为，就由司法机关追究该业务员的责任，与乙公司无关。经公安机关调查，发现乙公司公章使用管理混乱，使其业务员有伪造签章的可乘之机。

问：

乙公司和其业务员分别要承担什么责任？

阅读理解。

     For eighty four days old Santiago had not caught a single fish. At first a young boy, Manolin, had

shared his bad fortune, but after the fortieth luckless day the boy's father told his son to go in another

boat. From that time on, Santiago worked alone. The boy loved the old fisherman and  always helped

him with money and food. Usually, they would talk about the fish they had taken in luckier times or

about American baseball after supper, while at night, alone in his cottage, Santiago dreamed of lions on

the beaches of Africa, where he had gone years before. He no longer dreamed of his dead wife.

On the eighty-fifth day, Santiago set off to fish before dawn. Two of his baits (饵) were fresh tunas (金

枪鱼) the boy had given him, as well as sardines (沙丁鱼) to cover his hooks. Then he set his lines

which went straight down into deep dark water.

      As the sun rose he saw other boats in toward shore. A bird showed him where dolphin were chasing

some flying fish. This time Santiago saw tuna jumping in the sunlight. A small one took the hook on his

line. Pulling the fish aboard, the old man thought it a good fortune.

     Toward noon a marlin, a common fish in the sea, started eating the bait which was one hundred

meters down. Gently the old man played the fish, a big one, as he knew from the weight on the line. At

last he struck to settle the hook. The fish did not come out of the surface. Instead, it began to pull the

boat to the northwest. The old man followed it. Although he was alone and no longer strong, he had his

skill and knew many tricks. He waited patiently for the fish to be tired .

     It was cold after the sunset. When something took one of his remaining baits, he cut the line with his

knife. Once the marlin leaned suddenly, pulling Santiago forward on his face and cutting his cheek. By

dawn his left hand was cramped (抽筋的). The fish had headed northward; there was no land in sight.

Hungry, he cut pieces from the tuna and chewed them slowly.

     That morning the fish jumped. Seeing it, Santiago knew he had hooked the biggest marlin he had

ever seen. Then the fish went down and turned toward the east. Santiago drank a little water from the

bottle during the hot afternoon.

     Close to nightfall a dolphin took the small hook he had rebaited. He lifted it aboard, careful. After he

had rested, he cut meat from the dolphin and kept also the two flying fish he found in its stomach. That

night he slept. He awoke to feel the line running through his fingers as the fish jumped. Feeding line

slowly, he tried to tire the marlin. After the fish slowed its run, he washed his cut hands in sea water and

ate one of the flying fish. At sunrise the marlin began to circle. Faint, he worked to bring the big fish

nearer with each turn. Almost exhausted, he finally drew his big fish alongside and drove in the harpoon

(鱼叉). The fish was two feet longer than the boat. No fish like it had ever been seen in Havana harbor.

      An hour later, he sighted the first shark, a fierce Mako, and it came in fast to chase after the dead

marlin. The old man struck the shark with his harpoon. The Mako rolled and sank, carrying the harpoon

with it and leaving the marlin bloody. He knew the smell would spread. Watching, he saw two sharks

closing in. He struck at one with his knife and watched it sliding down into deep water. The other he

killed while it tore at the flesh of the marlin. When the third appeared, he thrust (刺) it with the knife.

The other sharks came at sunset. At first he tried to beat them with the tiller (舵柄) from the boat, but

his hands were bleeding and there were too many in the sea. In the darkness, as he steered toward the

harbor of Havana, he heard them hitting the boat again and again. But the old man thought only of his

steering and his great tiredness. He had gone out too far and the sharks had beaten him. He knew they

would leave him nothing but the stripped skeleton of the big marlin.

     All lights were out when he sailed into the little harbor and beached his boat. He could just make out

the white backbone and the upstanding tail of the fish. Once he fell under their weight and lay patiently

until he could gather his strength to go on. In his cottage he fell on his bed and went to sleep.

1. The above story is adapted from __________.

A. Treasure Island                

B. The Adventures Of Tom Sawyer

C. The Old Man And The Sea       

D. The Son Of The Sea

2. Why did the man feel that he could be lucky this time?

A. Because a small tuna took the hook on his line.

B. Because he dreamed about the American lions.

C. Because he saw many flying fish were chased by the dolphins.

D. Because a lot of sharks followed his boat.

3. According to the text, which statement is NOT true about Manolin?

A. The boy had mercy on Santiago.

B. The boy often shared his stories with Santiago.

C. The boy showed his great concerns to Santiago.

D. The boy was Santiago's adopted son.

4. Why does Santiago let the marlin lead his boat instead of pulling the big fish up? 

A. He wanted to kill the marlin first before he pulled it up to the boat.

B. He was too tired and hungry to pull the big fish up.

C. His experience told him not to do so before the fish was tired out.

D. He wanted to use the marlin as a bait to catch the sharks.

5. Which sentence below can be used to best describe Santiago's character?

A. "He no longer dreamed of his dead wife."(Para 1)

B. "Although he was alone and no longer strong, he had his skill and knew many tricks."(Para4)

C. "Almost exhausted, he finally drew his big fish alongside and drove in the harpoon."(Para7) 

D. "Once he fell under their weight and lay patiently until he could gather his strength to go on ."(Para 9)

6. According to the text, what will be talked about in the next paragraph?

A. the man's action to realize his dream about the lions.

B. people's reflection when they saw the giant marlin outside.

C. people's discussion about how they ate the giant marlin.

D. a funeral held by the boy and the local people after his death.

为什么说全民教育是解决当代人类困境的基本手段？ 

特殊区域环境保护

单向晶闸管（SCR）的结构，是由（）PN结组成的。

A.一个

B.两个

C.三个

D.四个