Cancer is used generically for more than 100 different diseases, including malignant tumors of different sites such as breast, stomach, colon, lung and mouth.【1】The disease arises principally as a consequence of individual exposure to the substances that cause cancer in what individuals inhale, eat and drink, or are exposed to in their personal or work environment. Personal habits, such as tobacco use, dietary and physical activity patterns—well as occupational and environmental conditions—rather than genetic factors, play the major roles in the development of cancer.
Many of the chronic diseases risk and the diseases themselves overlap. In developed countries, cancer is the second-biggest cause of death after cardiovascular disease (CVD), and epidemiological evidence points to this trend emerging in the less developed world. This is particularly true in countries of "transition" or middle income countries such as in South America and Asia. Already more than half of all cancer cases occur in developing countries.
There are approximately 20 million people living with cancer at the moment; by 2020 there will an estimated 30 million. And the impact is far greater than the number of cases alone would suggest.【2】Regardless of prognosis, the initial diagnosis is of- ten perceived by patients as life-threatening, with over one-third of sufferers experiencing clinical anxiety and depression. Cancer can also be profoundly distressing as well as economically disruptive to patients' families. The clinical care of cancer patients is a costly element in public health budgets.
【3】Dietary factors are estimated to account for approximately 30% of cancers in Western countries, making diet second only to tobacco as a preventable cause of cancer. This proportion is thought to be about 20% in developing countries and is projected to grow. As developing countries become urbanized, patterns of cancer, particularly those most strongly associated with diet and physical activity, tend to shift towards the patterns of economically developed countries. Cancer rates also change as populations move between countries and adopt different dietary patterns.
The relative importance of cancers as a cause of death is increasing. The incidence of lung cancer and cancers of the colon and breast generally increases in parallel with economic development, as stomach cancer declines. Cancer is also strongly associated with social and economic status. Cancer risk factors are highest in groups with the least education. In addition, patients in the lower socioeconomic classes have consistently poorer survival rates than those in higher social class.
In recent years, substantial evidence has pointed to the link from overweight and obesity, to many types of cancer such as breast and kidney.【4】The composition of the diet is also important since fruit and vegetables may have a protective effect by decreasing the risk for some cancer types such as oral and gastric cancer.
Regular physical activity has also been seen to have a protective effect in reducing the risk of breast cancer. High intake of preserved meat or red meat might be associated with increased risk of colorectal cancer. Another aspect of diet clearly related to cancer risk is the high consumption of alcoholic beverages, which convincingly increase the risk of oral cavity, liver and breast cancers.
The wealth of knowledge that already exists about cancer risk factors provides obvious and ample scope for action to reduce the cancer burden of all countries. After tobacco, overweight and obesity seems to be the most important avoidable cause of cancer.
【5】Given that poor nutrition, physical inactivity, obesity tobacco and alcohol are risk factors common to other chronic diseases such as CVD, type 2 diabetes, and respiratory diseases, conducting a cancer prevention program withi
Part B (10 points)
The volcano in the cornfield grew until it was bigger than the cornfield! (41)______ People called the volcano the Little Monster because it grew so fast. Scientists came from all over the world to study it and watch it grow. It is not often that people get a chance to watch a volcano from the very beginning.
Most of the volcanoes have been here for a very long time. Some have been here so long that now they are cold. They are called dead volcanoes. They have stopped throwing out fire and melted rock and smoke. It is safe to walk on them. Farms are plowed on the quiet slopes, and people have built houses there.
Some volcanoes have stopped throwing out hot rock, but they still smoke a little now and then. They are "sleeping" volcanoes. Sometime they may "wake up".
(42)______.
Today volcanoes are not so dangerous for people as they were a long time ago. Now we know more about why volcanoes do what they do, and we can usually tell when they are going to do it. (43)______.
People used to think dragons under the earth caused volcanoes. They said the smoke that puffed above the ground was the dragon's breath. They said the earthquakes were caused by the dragon's moving around down in the earth. Now we know that this is not true.
Another thing we know about volcanoes is that they don't happen just anywhere. (44)______. Scientists know where these places are, and maps have been made to let everybody know.
There are different kinds of volcanoes. Some explode so violently that the rock goes high into the air and falls miles away. A volcano may shoot out ashes so high that they float all the way around the world. They have made the sunsets green and the snow purple.
(45)______.
One very tall volcano stays fiery red at the top all the time. It is lucky that the volcano is near the ocean. Sailors can use it for a lighthouse.
[A] Other volcanoes are more gentle. The hot lava rises in their cones and overflows, rolling slowly down the mountainside, where it becomes cool and hard.
[B] Black smoke puffed out. Hot ashes fell like black snowflakes. Hot rock and fire and lava shot out.
[C] Smoke puffed up, and rock started popping up out of a crack that opened in the ground.
[D] A volcano named Vesuvius slept for a thousand years. But it woke up and threw out so much hot melted rock that it buried the buildings of two cities.
[E] Before a sleeping volcano wakes up, it usually makes a noise like faraway thunder, and the ground shakes in small earthquakes. People are warned and have time to get away safely.
[F] A volcano starts from a hole in the ground from which hot rock and smoke and steam come out. Far, far under the ground it is so hot that rock melts. This hot melted rock, or lava, is some-times pushed out of the earth through a hole or a crack in the ground. The steam inside the earth pushes the rock out.
[G] There are certain places under the earth where the rock is broken in a way that lets the steam and hot rock escape to the outside more easily.
(41)