问题 单项选择题

取某花类生药粉末,加浓氨水碱化后,氯仿浸提数次,浸提液挥去溶剂后,残渣加发烟硝酸蒸干后加无水乙醇及氢氧化钾,显紫色。此花类生药为()

A、丁香

B、槐米

C、洋金花

D、金银花

E、红花

答案

参考答案:C

单项选择题 A型题
单项选择题

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.

What does the author imply about lichens in Paragraph 1

A.They require a lot of moisture to live.

B.They primarily live in cold places.

C.They can live anywhere except around people.

D.They have adapted to a wide variety of environments.