Food sometimes gets poisoned with harmful things. A person who eats such food can get an illness
called food poisoning. Food poisoning is usually not serious, but some types are deadly. The symptoms
of food poisoning usually begin within hours of eating the poisoned food. Fever is one of the most
common symptoms.
Certain microorganisms(微生物)cause most types of food poisoning. Bacteria and other
microorganisms can poison eggs, meat, vegetables, and many other foods. After entering the body,
these tiny living things release poisons that make people sick.
Some chemicals can also cause food poisoning. They are often added to food while it is being grown,
processed, or prepared. For example, many farmers spray chemicals on crops to kill weeds and insects.
Some people may have a bad reaction to those chemicals when they eat the crops.
Some plants and animals contain natural poisons that are harmful to people. These include certain
kinds of seafood, grains, nuts, seeds, beans, and mushrooms.
When people handle food properly, the risk of food poisoning is very small. Microorganisms multiply
rapidly in dirty places and in warm temperatures. This means that people should never touch food with
dirty hands or put food on unwashed surfaces. Food should be kept in a refrigerator to stop
microorganisms from growing. Meat needs to be cooked thoroughly to kill any dangerous
microorganisms. People should also wash food covered with chemicals before eating it. Finally, people
should not eat wild mushrooms or other foods that grow in the wild. Some of these foods may contain
natural materials that are poisonous to humans. In addition, some types of fish can be poisonous.
Most people recover from food poisoning after a few days of resting and drinking extra water. If
people eat natural poisons, they must go to the hospital right away to have their stomachs emptied.
1. Which of the following statements is NOT true?
A. Food poisoning means death.
B. Food poisoning can be serious.
C. Food poisoning comes in varieties.
D. Food when poisoned can make people sick.
2. We know from the passage that the symptoms of food poisoning .
A. can be noticed within hours
B. can be ignored
C. are too common to be noted
D. are always accompanied by a fever
3. Food poisoning can be caused by all the following EXCEPT .
A. some chemicals
B. low temperatures
C. some tiny living things
D. certain natural materials
4. From Paragraph 5, we can learn that .
A. mushrooms should not be eaten
B. vegetables are safer than meat and seafood
C. natural poisons are more dangerous than chemicals
D. different types of food should be handled differently
5. It can be inferred from the passage that .
A. natural materials are safe in food processing
B. food poisoning can be kept under control
C. chemicals are needed in food processing
D. food poisoning is out of control
Cl2（g）＋CO（g）；△H＝＋108kJ·mol－1。反应体系中各物质的浓度在不同条件下的变化如图8所示（10～14 min的COCl2浓度变化未标出）：