阅读理解。
The cold wind cut through my enthusiasm (热情) as a tourist in Washington D.C., so I entered the
nearest restaurant for warmth. I ordered a coffee, and began observing people.
At that time, I saw a man seated nearby and from his eager eyes, I realized that he noticed the
delicious food. His tired body and worn clothes shouted, "Homeless, homeless!"
"How long has it been since he ate last time?" I wondered. I expected him to approach me for a
handout (施舍物). But he never did. A silent war broke out in my head-one side was telling me to mind
my own business, and the other was urging me to offer him some food.
While my inner debate moved on, a well-dressed young couple walked up to him. "Excuse me, sir,
"the husband began. "We just finished eating, and our appetites (胃口) weren't as big as we had thought. We hate to waste good food. Can you help us out and put this to use?" He gave the man some food.
"Thank you. Merry Christmas!" the man replied. The man carefully watched his new food, and was about
to eat.
Something that happened next shocked me. An old man in pants, an old jacket and open shoes
entered the hall and walked towards us. My neighbor saw the situation. Setting aside his meal, he stood
up and guided the old man to the table.
"Hi, my name is Jack," he said, "and one kind person brought me this meal. I just finished eating and
hate to waste good food. Can you help me out?" The old man answered gratefully, "Sure, but only if you
go halfway with me on that sandwich."
I left the restaurant that day feeling warmer than I had ever thought possible.
1.The author entered the nearest restaurant to .
A. escape the coldness outside
B .taste the delicious coffee
C. relax as a tourist
D. enjoy watching other people
2. What can we learn about the old man according to the text?
A. He accepted the food given by the kind couple.
B. He felt ashamed because of his own appearance.
C. He expressed thanks to Jack after being helped by him.
D. He had known Jack before he entered the restaurant.
3. It can be inferred from the text that .
A. the young couple always wasted food in the restaurant
B. the old man accepted all the food given by Jack
C. Jack was disappointed that the author didn't help him
D. Jack gave the food to the old man though he was still hungry
4. What can be the best title of the text?
A. The Couple's Kindness
B. Drawn to the Warmth
C. A Delicious Dinner
D. A Homeless Man
Na2CO3+CO2↑+H2O，Na2CO3受热不分解，根据CO2为0.02mol可知NaHCO3为0.04mol则NaHCO3为0.04mol×84g/mol=3.36g。Na2CO3为4.42g-3.36g=1.06g。