英語翻譯
Passage 13 How can you find out what is going on inside a person’s body without opening the patient’s body up?Regular X rays can show a lot.CAT scans（掃描儀）can show even more.They can give a complete view of body organs（器官）.
What is a CAT scan?CAT stands for a kind of machine.It is a special X-ray machine that gets a 360-degree picture of a small area of a patient’s body.
Doctors use X rays to study and determine diseases and injuries within the body.X rays can find a foreign object inside the body or take pictures of some inside organs to be X-rayed.
A CAT scanner,however,uses a group of X rays to give a cross-sectional（橫截面）view of a specific part of the body.A fine group of X rays is scanned across the body and around the patient from many different directions.A computer studies the information form each direction and produces a clear cross-sectional picture on a screen.This picture is then photographed for later use.Several cross sections,taken one after another,can give clear “photos” of the entire body or of any body organs.The newest CAT scanners can even give clear pictures of active,moving organs,just as a fast-action camera can “stop the action”,giving clear pictures of what appears unclear to the eye.And because of the 360-degree pictures,CAT scans show clear and complete views of organs in a manner that was once only shown during operation or examination of a dead patient.
Frequent appearance before X rays can cause skin burns,cancer or other damage to the body.Yet CAT scans actually don’t cause the patient to more radiation（輻射）than regular X rays do.CAT scans can also be done without getting something harmful into the patient,so they are less risky that regular X rays.
CAT scans provide exact,detailed information.They can quickly find such a thing as bleeding inside the brain.They are helping to save lives.
Passage 16 Can we live without salt?Salt is very important to us.We need salt in our food.Animals need it,too.Most of the salt in our country comes from the sea.People dig very big pools (池塘) and let sea water in .When the sun dries (弄干) up the water,people can get salt from the ground.The salt is white,clean and beautiful.
There are a lot of salt wells (井) in Sichuan.A salt well is much like a water well.People bring the well water up to the ground and then dry it in big jars (壇子) over fire.In this way they get salt.We can also get salt from salt mines (礦).A salt mine may be found under the ground.Some years ago,people in Jiangxi found a big salt mine and soon opened it.People here need salt from other places no more.
In the northwest of our country,there are many salt lakes.Some of these lakes are very big.The salt in a big lake will be enough for our people for centuries.