Sea horses are unusual parents. The female sea horses lay the eggs, but unlike other creatures, it's the males that give birth to the young.
Male sea horses have a fold of skin on their bellies that forms pocket, called a brood pouch. During the breeding season, the sea horse's pouch swells to receive eggs. A female sea horse lays up to 200 eggs at a time in the pouch. Then she swims off, leaving her male partner to care for the developing eggs and give birth to young sea horses. The female will return everyday to check on her mate and the eggs, but she doesn't stay long, nor does she take part in the birth.
It takes from two to six weeks for the eggs in the male's pouch to develop. During this time the male avoids open water and hides in sea grass. His big pouch makes it difficult for him to swim, so the male often uses his tail to grasp a piece of sea grass. Firmly gripping the grass, he will stay perfectly still for hours or even days. The male sea horse will change his color to blend with his surroundings and avoid being seen by predators who will try to eat him or poke holes in his pouch to get the eggs.
The eggs hatch inside the male's pouch. When the babies begin moving around, the male sea horse knows it's time for them to be born. He grabs a sea grass stem with his tail and begins rocking, bending, and stretching his body so that the rest of the babies can be born. Sometimes he has to press his pouch against a rock Or some stiff seaweed to force the young out.
Sea horse babies are born in groups of five or more. Sometimes it takes two days for the father sea horse to give birth to all his young. He is very tired when it's over.
Soon after giving birth to one brood, the male will approach his mate and show her his empty pouch. This tells her he is ready to receive eggs again.
What part does the female sea horse play in having babies?
A.Receiving eggs.
B.Laying eggs.
C.Hatching eggs.
D.Protecting eggs.
Trying to get Americans to eat a healthy diet is a frustrating business. Even the best-designed public-health campaigns cannot seem to compete with the tempting flavors of the snack-food and fast-food industries and their fat-and sugar-laden products. The results are apparent on a walk down any American street—more than 60% of Americans are overweight, and a full quarter of them are overweight to the point of obesity.
Now, health advocates say, an ill-conceived redesign-has taken one of the more successful public-health campaigns—the Food Guide Pyramid—and rendered it confusing to the point of uselessness. Some of these critics worry that America's Department of Agriculture caved to pressure from parts of the food industry anxious to protect theft products.
The Food Guide Pyramid was a graphic which emphasizes that a healthy diet is built on a base of gains, vegetables and fruits, followed by ever-decreasing amounts of dairy products, meat, sweets and oils. The agriculture department launched the pyramid in 1992 to replace its previous program, which was centered on the idea of four basic food groups. The "Basic Four" campaign showed a plate divided into quarters, and seemed to imply that meat and dairy products should make up haft of a healthy diet, with grains, fruits and vegetables making up the other half. It was replaced only over the strenuous objections of the meat and dairy industries.
The old pyramid was undoubtedly imperfect. It failed to distinguish between a doughnut and a whole-grain roll, or a hamburger and a skinless chicken breast, and it did not make clear exactly how much of each foodstuff to eat. It did, however, manage to convey the basic idea of proper proportions in an easily understandable way. The new pyramid, called "My Pyramid", abandons the effort to provide this information. Instead, it has been simplified to a mere logo. The food groups are replaced with unlabelled, multi-colored vertical stripes which, in some versions, rise out of a cartoon jumble of foods that look like the aftermath of a riot at a grocery store. Anyone who wants to see how this translates into a healthy diet is invited to go to a website, put in their age, sex and activity level, and get a custom-designed pyramid, complete with healthy food choices and suggested portion sizes. This is free for those who are motivated, but might prove too much effort for those who most need such information.
Admittedly, the designers of the new pyramid had a tough job to do. They were supposed to condense the advice in the 84-page United States' Dietary Guidelines into a simple, meaningful graphic suitable for printing on the back of a cereal box. And they had to do this in the face of pressure from dozens of special interest groups—from the country's Potato Board, which thought potatoes would look nice in the picture, to the Almond Board of California, which felt the same way about almonds. Even the National Watermelon Promotion Board and the California Avocado Commission were eager to see their products recognized.
Nevertheless, many health advocates believe the new graphic is a missed opportunity. Although officials insist industry pressure had nothing to do with the eventual design, some critics suspect that political influence was at work. On the other hand, it is not clear how much good even the best graphic could do. Surveys found that 80% of Americans recognized the old Food Guide Pyramid—a big success in the world of public-health campaigns. Yet only 16% followed its advice.
Trying to get Americans to eat a healthy diet is a frustrating business can be easily proved by the fact that
A.public-health campaigns cannot compete with tempting flavors.
B.snack-food and fast-food industries are flourishing in the US.
C.most food in America are profoundly rich in fat and sugar.
D.fat people account for a large proportion of American population.
Human beings are animals. We breathe, eat and digest, and reproduce the same life【B1】common to all animals. In a biological laboratory, rats, monkeys, and humans seem very much the same.
However, biological understanding is not enough:【B2】itself, it can never tell us what human beings are.【B3】to our physical equipment—the naked human body—we are not an【B4】animal. We are tropical creatures,【B5】hairless and sensitive to cold. We are not fast and have neither claws nor sharp teeth to defend ourselves. We need a lot of food but have almost no physical equipment to help us get it. In the purely physical【B6】, our species seems a poor【B7】for survival.
But we have survived—survived and multiplied and【B8】the earth. Some day we will have a【B9】living on the moon, a place with neither air nor water and with temperatures that turn gases into solids. How can we have done all these things? Part of the answer is physical.【B10】its limitations, our physical equipment has some important potentials.
Inhabitants of our eventual moon colony will bring their own food and oxygen and then create an artificial earth environment to supply necessities.
【B1】
A.processes
B.acts
C.modes
D.procedures