单选题
{{B}}Directions:{{/B}} There are 10 questions in this part of the test. Read the
passage through. Then, go back and choose one suitable word or phrase marked A,
B, C, or D for each blank in the passage. Mark the corresponding letter of the
word or phrase you have chosen with a single bar across the square brackets on
your machine-scoring Answer Sheet. An
ecosystem is defined as an ecological community together with its environment,
functioning as a unit. To be more {{U}} {{U}} 1 {{/U}} {{/U}},
an ecosystem is a complex set of relationships among the living resources,
{{U}} {{U}} 2 {{/U}} {{/U}}, and residents of an area, composed
of organisms that work together to remain healthy {{U}} {{U}} 3
{{/U}} {{/U}}energy is exchanged and system-level processes emerge. The
ecosystem serves as the level of biological organization in which organisms
{{U}} {{U}} 4 {{/U}} {{/U}}simultaneously with each other and
with their environment. As such, ecosystems are a level above that of the
ecological community but are at a level below the {{U}} {{U}} 5
{{/U}} {{/U}}, which is essentially the largest of all possible
ecosystems. The thing about ecosystems is that they are
{{U}} {{U}} 6 {{/U}} {{/U}}fragile and intensely complicated. If
you influence the smallest variable, then it changes the {{U}} {{U}}
7 {{/U}} {{/U}}. This is why global warming is such a big issue,
{{U}} {{U}} 8 {{/U}} {{/U}}whether we created it or not.
Ecosystems will change; however, if they change radically enough, our way of
life will forever be affected. It is sad to think that future generations will
not have the {{U}} {{U}} 9 {{/U}} {{/U}}of witnessing these
little creatures as we have in our lifetime. You have to go to preservations to
witness the wildlife that {{U}} {{U}} 10 {{/U}} {{/U}}be an
everyday occurrence.
单选题
A. realistic
B. frank
C. honest
D. specific
【正确答案】
D
【答案解析】[解析] 文章的第一句是生态系统的粗略定义。第二句以后详细解释生态系统的组成、运行原理和各种关系。to be frank：坦率地说；to be honest：说句实话；to be more specific：更明确地说。根据前后句的关系，to be more specific更合适。