某地拟在近海建一混合码头，设计油品泊位3个，煤炭泊位2个，散杂货泊位3个。码头所在近海一带现状以水产养殖业为主。拟建工程占用陆域面积270hm2，同时，需填海造地10hm2。征地无拆迁，但防护距离范围内是否有居民尚需调查。除港池疏浚约600万方外，陆地工程挖方量60万方，填方量157万方。距码头占地区8km有一省级自然保护区，距码头10km的海域有一岛礁旅游度假风景区。
简述工程施工期可能对近岸海域造成的影响。
参考答案：主要是码头工程填海造地施工及港池疏浚作业影响，包括施工期产生的施工污水、生活污水排放的影响，港池疏浚产生的悬浮物、噪声、含油污水对近岸海域水质及海洋生物将造成不良影响。施工期扬尘、固体废物对海域的影响等。
| Lichens may grow on the bark of a tree in a steaming tropical rain forest, on the bricks of big city buildings, on rocks in hot springs, on wind-swept mountaintops, and in the driest desserts. In the arctic, they provide the principal food for caribou, and they are one of the few plants that grow in Antarctica. They are pioneers, appearing in barren rocky areas and starting the formation of soil in which mosses, then ferns, and then other plants can take root. Lichens are a partnership of two plants — fungi and algae. The lichen body is made up of a network of fungal strands. In the upper layers of these grow groups of algae. The two organisms live together to the benefit of both, a relationship known as symbiosis. The fungi provide support, absorb water, and shelter the tender algae from direct sunlight. The algae carry on photosynthesis and provide the fungi with food. The algae can live independently and are recognizable as a species that grows alone. The fungi, on the other hand, cannot live apart from their partners. They can be placed in known classes of fungi but are unlike any species that lives independently. So definite are the form, color, and characteristics of these double organisms that for hundreds of years, they were classified as one. More than 15,000 "species" were named. If these organisms are classified as separate species, it is difficult to fit them into the existing system of classification. But if they are classified separately, these species of fungi seem rather strange. Lichens are a splendid example of the difficulties faced by taxonomists in classifying species. |
Which of the following best expresses the main idea of Paragraph 2
A．Because of their characteristics as double organisms, it is difficult to classify lichens.
B．Over 15,000 varieties of lichens have been identified.
C．Double organisms should always be classified as separate species.
D．Taxonomists always find it difficult to classify new species of plants.