一个导体两端加4 V电压时，通过它的电流为0.8 A，当把它两端电压变为6 V时
题型：填空题
问题：
一个导体两端加4 V电压时，通过它的电流为0.8 A，当把它两端电压变为6 V时，通过它的电流为_____A，它的电阻为_____Ω；当该导体两端电压降为0V时，通过它的电流为_____A，它的电阻为____Ω.
题型：填空题
One morning last summer Joyce Andrews made some sausage sandwiches for her husband’s lunch. There was one sausage left over. Mrs. Andrews didn’t care for them herself, and so she gave to last one to Henry, their little dog, Henry ate it up quickly.
During the morning the dog got ill. He wouldn’t stop shaking his head, and couldn’t stand properly. Joyce thought, “He’s eaten something that didn’t agree with him. Maybe that sausage very bad…” she suddenly remembered her husband’s lunch. She ran to the telephone and called Jim at office.
“Jim, I hope you haven’t eaten any of those sandwiches yet.”
“You have? Two? Well, listen—don’t eat any more. I gave Henry the last sausage, and new he’s ill. Go to 
the doctor, Jim.”
“What? You feel all right? No, Jim, don’t take a chance with your health. I’m sure the sausages are bad. Please go…”
“Yes, Jim. Tell him about the dog. Get some medicine.”
Jim came back at lunch time and went to bed. “I had a very unpleasant hour at the doctor” he told Joyce, “and the medicine made me very sick.”
The next morning Jim was fine. Henry seemed quite fit again,
too. At eleven o’clock milkman came with the milk. 
“Morning, Mrs. Andrews,” the milkman said “How’s your dog this morning? I’ve been thinking about him…”
“Have you? Well, he seems all right now, but...”
“Yesterday morning he and I had I a little accident. He jumped up at me, and I dropped a bottle of milk on his head.”
67. Why did Joyce telephone Jim?
A. She wanted him to come home for lunch
B. Jim’s dog was badly ill.
C. Jim was ill and needed to go to the hospital
D. She thought the sausage would do harm to him
68. Joyce’s husband ________.
A. took her advice that he should go to the hospital B. didn’t believe her
C. knew why Henry kept shaking his head D. didn’t eat any of the sausage
69. Which of the following is TRUE according to the text?
A. It was the sausage that made Henry ill.
B. Jim ate only two sandwiches, so he was quite all right.
C. The milkman explained Henry’s illness
D. Jim felt unpleasant because of her wife’s telephone call.
70. The underlined word “him” probably refers to _________.
A. Jim B. the milkman C. the doctor D. Jim’s dog