英语高手请进帮忙做几个单选,多谢了

英语高手请进帮忙做几个单选,多谢了
7-11 单选题
7 There are different ways in which people try to deal with the problem of energy. One way is the greater production of common energy sources, such as coal, oil and gas. The trouble with these sources, however, is that they are not renewable.
Another way is energy conservation (节能), which means using energy more efficiently (有效地). In some very cold countries people build special houses to save energy. They place materials between the inside and the outside of the walls of the house to keep the cold out and the warmth in. The house is heated by the lights, the body heat of the people and the other equipment in it.
Finally, renewable energy sources are used even though they are often expensive to develop. One form of these is geothermal energy. In certain parts of the world the temperature of the earth increases thirty degrees centigrade with each kilometer down. At six kilometers, therefore, it rises to nearly two hundred degrees. To get the heat, water is pumped (压；抽) down into the rocks and back up to the surface. Heat from the earth is already used in certain countries.
From the text we learn that coal__.
a、is quite easy to produce
b、is not used most efficiently
c、is the most common source of energy
d、could be renewed only by new technology
8 The police announced that there will be an official _____ into the mysterious death.
a、inscription
b、input
c、inquiry
d、irony
9 Most animals have little connection with animals of different kind, unless they hunt them for food. Sometimes, however, two kinds of animals come together in a partnership (伙伴关系) which does good to both of them. You may have noticed some birds sitting on the backs of sheep. This is not because they want a ride, but because they find easy food in the parasites （寄生虫) on sheep. The sheep allow the birds to do so because they remove the cause of discomfort. So although they can manage without each other, they do better together.
Sometimes an animal has a plant partner. The relationship develops until the two partners cannot manage without each other. This is so in the corals (珊瑚) of the sea. In their skins they have tiny plants act as "dustman", taking some of the waste products form the corals and giving in return oxygen which the animal needs to breathe. If the plants are killed, or are ever prevented from lighting so that they cannot live normally, the corals will die.
What does this article talk about?
a、Two kinds of animals for a partnership.
b、Most animals only have connection with animals.
c、The connection between the living things
d、Corals have some connection with plants.
10 He was a kind man and _______ agreed to help us out.
a、readily
b、reluctantly
c、quickly
d、absolutely
11 Debbie has a(n) _____ that we have not heard the whole truth about this matter yet.
a、uncertainty
b、distrust
c、suspicion
d、doubt