世界通行的医疗社会保险待遇支付做法有哪些？我国基本医疗社会保险待遇采用什么样的支付方

下图是某草原生态系统的部分生物，请据图回答；

(1)图中有_________条食物链。

(2)图中最长的一条食物链是___________。最短的一条食物链是_____________。

(3)每条食物链的起点生物是___________，属于生态系统的_____________成分。

(4)由于长时间干旱，这个生态系统中的青草全都枯死了，最先受到影响的动物是___________。

对某高校本科生的某项调查统计发现：在因成绩优异被推荐免试攻读硕士研究生的文科专业学生中，女生占有70%，由此可见，该校本科生文科专业的女生比男生优秀。
以下哪项如果为真，能最有力地削弱上述结论( )

A．在该校本科生文科专业学生中，女生占30%以上
B．在该校本科生文科专业学生中，男生占30%以上
C．在该校本科生文科专业学生中，男生占30%以下
D．在该校本科生文科专业学生中，女生占70%以下

During recent years, floods and flash floods have caused billions of dollars in damage each year. They are among the most common and widespread of all natural disasters. Even more importantly, they’re No.1 weather-related killer. A flood can happen anywhere along the Mississippi, in New England, even in the desert.

The following are some fascinating facts about floods and flash floods.

A flood（commonly called river flood）is high flow of water from a river or similar body of water, happening over a period of time too long to be considered a flash flood. Flooding is caused in many ways. Winter or spring rains, together with melting snows, can fill rivers too quickly. Heavy rains from hurricanes or other tropical（热带的）systems can also produce river flooding. The Mississippi River Flood of 1993 was caused by repeated heavy rain from thunderstorms over a period of weeks.

Flash floods are quickly-rising floods which are usually the result of heavy rains over a short period of time, often only several hours or even less. They can also be caused by ice jams（冰塞）on rivers related to a winter or spring melting, or occasionally even a dam break. The constant influx（汇集） of water finally caused a great overflow to begin, powerful enough to sweep vehicles away, roll big stones into roadways, uproot trees, level（夷平） buildings, and knock bridges down. The speed of the rising of water is the most frightening.

Do remember: Move to higher ground and stay away from low areas during heavy rain. Stay out of flooded areas. Never allow children especially to play or walk in flowing water. Never drive your car into water of unknown depths.

43. What is the best title for the passage?

A. The power of floods              B. The damage of floods

C. The occurrence of floods           D. The facts about floods

44. The last paragraph is mainly about ______ .          

A. flood safety tips                B. the reasons for floods

C. the waste water systems              D. the swift flood waters

45. According to the passage, people are afraid of _____ most during flash floods.

A. the constant influx of water

B. the sudden occurrence of flash floods

C. the quick rising water

D. the great damage of flash floods

46. According to the passage, flash floods are ______.

A. great floods resulted from heavy rains in a short time

B. floods rising quickly from heavy rains in a short time

C. quickly-rising floods in a long time

D. floods happening over a long time

不符合腹主动脉瘤声像图特点的是（）。

A.腹主动脉呈囊状或梭形局限性扩张

B.腹主动脉管壁连续性中断，断裂处与腹主动脉旁血肿低回声相连通

C.瘤腔与两端正常腹主动脉腔连通

D.腹主动脉瘤壁间合并血栓时，管壁增厚

E.腹主动脉瘤的彩色血流与腹主动脉彩色血流一致

成形磨削