听觉障碍学生思维最大的特点是：（）

世界人口最稠密的地区多分布在（　　）

A．热带沿海

B．温带沿海

C．热带雨林

D．温带内陆

病历摘要：患者女性，28岁。因双耳渐进性听力下降、耳鸣，时有耳内发堵8年。在当地医院诊断为分泌性中耳炎，给予波氏球打气，每天行鼓膜按摩及滴鼻剂治疗未好转，行左鼓膜穿刺，未抽出液体。患者来我院就诊，耳镜检查见鼓膜完整，稍内陷，查纯音测听：右耳传导性聋，左耳混合型聋，声阻抗：右耳A型，左耳As型，盖莱试验右耳（+），左耳（-）。

属于耳硬化症手术治疗的术式包括（）提示：该患者确诊为耳硬化症

A.镫骨切除术

B.外半规管开窗术

C.镫骨撼动术

D.内淋巴引流术

E.迷路切除术

F.镫骨足板钻孔活塞术

G.镫骨足板破碎术

H.前庭神经切除术

急性肠炎所致的腹泻属于（）

A.吸收不良性

B.渗出性

C.渗透性

D.分泌性

E.动力性

About fifty years ago, plant physiologists set out to grow roots by themselves in solutions in laboratory flasks. The scientists found that the nutrition of isolated roots was quite simple. They required sugar and the usual minerals and vitamins. However, they did not require organic nitrogen compounds. These roots got along fine on mineral inorganic nitrogen. Roots are capable of making their own proteins and other organic compounds. These activities by roots require energy, of course. The process of respiration uses sugar to make the high energy compound ATP, which drives the biochemical reactions. Respiration also requires oxygen. Highly active roots require a good deal of oxygen.The study of isolated roots has provided an understanding of the relationship between shoots and roots in intact plants. The leaves of the shoots provide the roots with sugar and vitamins, and the roots provide the shoots with water and minerals. In addition, roots can provide the shoots with organic nitrogen compounds. This comes in handy for the growth of buds in the early spring when leaves are not yet functioning. Once leaves begin photosynthesizing, they produce protein, but only mature leaves can "export" protein to the rest of the plant in the form of amino acids.

The scientists found what the isolated roots need is________.

A．quite natural

B．sugar, minerals and vitamins

C．some rare vitamins

D．organic nitrogen compounds

北京京维纸业有限公司属于外商独资企业，专营纸张制造。该公司于2007年9月与日本某公司签约购买一台价值为CIF780000美元，在投资总额内的造纸设备。但因该纸业公司的资金比较紧张，经双方协商达成协议，协议规定纸业公司以该设备生产的“手工制造书写纸”回抵设备的价款。该设备属于《外商投资产业指导目录》中的鼓励类进口顷目。该设备于2007年10月2日由江天运输公司的“JUL0NGVOY/501”轮船载运，在天津新港进口。京维纸业公司委托通达物流有限公司代理报关，通达公司于2007年10月7日向天津海关办理转关申请后由汽车运抵北京(该设备属《机电产品自动进口许可证》管理范围，法定检验，该设备进口具有全程提单)。
根据上述材料，回答下列问题：

本案中，贸易方式为：( )。

A．互购

B．易货贸易

C．补偿贸易

D．转手贸易