Luyện thi THPT quốc gia môn Anh theo chuyên đề: Phần đọc hiểu

But not all animal parents, even those that tend their offspring to the point of hatching or birth, feed their young. Most egg-guarding fish do not, for the simple reason that their young are so much smaller than the parents and eat food that is also much smaller than the food eaten by adults. In reptiles, the crocodile mother protects her young after they have hatched and takes them down to the water, where they will find food, but she does not actually feed them. Few insects feed their young after hatching, but some make other arrangement, provisioning their cells and nests with caterpillars and spiders that they have paralyzed with their venom and stored in a state of suspended animation so that their larvae might have a supply of fresh food when they hatch.

For animals other than mammals, then, feeding is not intrinsic to parental care. Animals add it to their reproductive strategies to give them an edgein their lifelong quest for descendants. The most vulnerable moment in any animal's life is when it first finds itself completely on its own, when it must forage and fend for itself. Feeding postpones that moment until a young animal has grown to such a size that it is better able to cope. Young that are fed by their parents become nutritionally independent at a much greater fraction of their full adult size. And in the meantime those young areshielded against the vagaries of fluctuating of difficult-to-find supplies. Once a species does take the step of feeding its young, the young become totally dependent on the extra effort. If both parents are removed, the young generally do not survive.

The women had primary responsibility for the fields. They had to exercise considerable skill to produce the desired results, for their northern location meant fleeting growing seasons. Winter often lingered; autumn could be ushered in by severe frost. For good measure, during the spring and summer, drought, heat, hail, grasshoppers, and other frustrations might await the wary grower.

Under such conditions, Mandan women had to grow maize capable of weathering adversity. They began as early as it appeared feasible to do so in the spring, clearing the land, using fire to clear stubble from the fields and then planting. From this point until the first green corn could be harvested, the crop required labor and vigilance.

Harvesting proceeded in two stages. In August the Mandans picked a smaller amount of the crop before it had matured fully. This green corn was boiled, dried and shelled, with some of the maize slated for immediate consumption and the rest stored in animal – skin bags. Later in the fall, the people picked the rest of the corn. They saved the best of the harvest for seeds or for trade, with the remainder eaten right away or stored for alter use in underground reserves. With appropriate banking of the extra food, the Mandans protected themselves against the disaster of crop failure and accompany hunger.

The woman planted another staple, squash, about the first of June, and harvested it near the time of the green corn harvest. After they picked it, they sliced it, dried it, and strung the slices before they stored them. Once again, they saved the seeds from the best of the year’s crop. The Mandans also grew sunflowers and tobacco; the latter was the particular task of the older men.