A、It will do more harm to the stomach. B、It may be harmful to the throat in the process. C、It can’t force the poisoning things t

Doctors in hospital emergency rooms often see accidental poisonings. A frightened parent arrives with a child who swallowed a cleaning liquid. Or perhaps the harmful substance is a medicine. Or it might be a product meant to kill insects. These are common causes of accidental poisoning. In cases like this, seek medical help as soon as possible. Save the container of whatever caused the poisoning. And look on the container for information about anything that stops the effects of the poison. In the past, some people forced poisoning victims to empty the stomach. They used a liquid to do this. But a leading medical organization no longer advises this. They say some poisons can cause additional damage when they come back up the throat. Millions of people know how to give abdominal thrusts to save a person choking on something trapped in the throat. The American Red Cross says a rescuer should first hit the person on the back five times between the shoulder bones. These back blows may ease the choking. If the airway is still blocked, the Red Cross suggests pushing hard five times along the victim’s abdomen. Red Cross experts say taking these steps can save many lives. But they also say abdominal thrusts are not for people who have almost drowned. They say using the method could delay other ways to restart breathing in the victim. If you know first aid methods, you can be calmer and more helpful in case of emergency.
Questions 20 to 22 are based on the passage you have just heard.
20. What can parents do to give first aid to poisoning children?
21. Why is emptying the stomach of poisoning victims not advised?
22. What is the passage mainly about?