硅橡胶应用较广泛，下列不正确的是（） A.人造器官 C.皮下埋植剂 B.子宫避孕器

寻找病因应做哪项检查

A．放射性核素骨扫描

B．妇科检查

C．⁵¹Cr红细胞半寿命期测定

D．钡剂灌肠

E．胸部X线检查

读下列材料回答下列问题。（10分）

材料一：我国某地区化肥消费量与小麦单产变化图（图甲）

材料二：农民生产施肥习惯表（图乙）

甲                            乙

（1）结合资料，说明我国化肥消费量与谷物单产的变化趋势。（4分）

（2）若该地区农民施肥习惯不变，可能产生哪些环境问题？在今后生产中应采取什么措施？（6分）

稳压二极管可以并联使用。

In our society, we must communicate with other people. A great deal of communicating is performed on a person-to-person (1) by the simple means of speech. If we travel in buses, stand in football match (2) , we are likely to have conversations (3) we give information or opinions, and sometimes have our views (4) by other members of society.

Face-to-face contact is (5) the only form of communication, and during the last two hundred years the (6) of mass communication has become one of the dominating factors of contemporary society. Two things, (7) others, have caused the enormous growth of the communication industry. Firstly, inventiveness has (8) advances in printing, photography and so on. Secondly, speed has revolutionized the (9) and reception of communications so that local news often (10) a back seat to national news.

No longer is the possession of information (11) to a privileged minority. Forty years ago people used to (12) to the cinema, but now far more people sit at home and turn on the TV to watch a program that (13) into millions of houses. Communication is no longer merely concerned (14) the transmission of information. The modern communications industry influences the way people live in society and broadens their horizons by allowing (15) to information, education and entertainment. The printing, broadcasting and advertising industries are all (16) with informing, educating and entertaining. (17) a great deal of the material communicated by the mass media is very valuable to the individual and to the society (18) which he is a part, the vast modern network of communications is (19) to abuse. However, the mass media are with us for better, for worse, and there is no turning (20) .

3（）

A.whereas

B.which

C.that

D.where

已知植物根系可以通过细胞间隙的扩散和活细胞的转运两种途径吸收矿质元素。科学家为研究根系吸收矿质元素的规律，分别在正常条件和缺氧条件下用含有42K完全培养液培养大麦，得到如图所示结果。

正常条件和缺氧条件对第一阶段和第二阶段影响不同。第一阶段42K进入根系的过程（）（不受、受）代谢控制；第二阶段是42K进入（）（细胞间隙、细胞内）的转运过程，其运输方式为（）。