When you hear the word quicksand, what image comes to mind? You probably picture someone up to the waist in wet land, screaming for help. In fact, quicksand can be very dangerous. People and animals have sunk into quicksand before and never escaped. However, the more you know about quicksand, the safer you will be.
First, quicksand is really ordinary sand. It isn’t some sort of strange hungry beast. Quicksand forms when water seeps up (渗出) from the underneath a layer of fine sand. The water pushes the grains of sand apart and makes the sand loose. This loose sand will not hold up a heavy weight.
Quicksand usually forms along the banks of rivers, at the seashore, or under slow-moving rivers and streams. It only forms when water flows upward through the sand, not over it. If you are in a place that tends to have quicksand, it’s a good idea to carry a large stick. As you walk, poke (戳) the ground in front of you to be sure it’s firm.
Let’s suppose that you happen to step into some quicksand. The best way to deal with it is to stay calm. You may sink, but you won’t sink quickly. You will have time to try several ways to get out. First, drop anything you might be carrying that adds weight, such as a backpack. Then try walking out -making slow and steady movements with your legs. If this doesn’t work, the best thing to do is lie back and float, it’s even easier to float on quicksand than on regular water.
Of course, you will want to call for help. If help is nearby, it’s best simply to wait. If help is not nearby, then continue to lie on your back but make slow, rolling movements toward the edge of the quicksand. When you feel solid ground underneath, you can stand up.
Some animals seem to know how to avoid sinking down into quicksand. Mules, for instance, fold their legs underneath them and float on their bellies. Cows, on the other hand, tend to panic and wave their legs around. This doesn’t help them escape. So, if you are ever trapped in quicksand, think like a mule, not like a cow.
56. What detail supports the idea that quicksand can be dangerous?
A. Quicksand forms when water seeps up from underneath.
B. You will have time to try several ways to get out.
C. Animals have fallen into quicksand and never escaped.
D. Quicksand is really just an ordinary sand.
57. If you get caught, what should you do first?
A. Wave your arms and legs quickly.
B. Drop anything heavy that you are carrying.
C. Fold your legs underneath you.
D. Poke a stick into the ground in front of you.
58. How is the mule’s reaction to quicksand different from a cow’s reaction?
A. Mules fold their legs and float on their bellies.
B. Mules wave their legs around.
C. Mules sink immediately.
D. Mules panic and splash their legs around.
59. What’s the passage about?
A. Quicksand is not really made up of sand.
B. Quicksand can be dangerous, but there are ways to escape.
C. You should poke the ground in front of you with a stick.
D. Animals are able to float on quicksand, but humans always sink.
60. The author’s main purpose in this passage is to _______________.
A. give information about quicksand
B. tell an entertaining story
C. persuade people to avoid quicksand
D. explain how quicksand forms