生命伦理学当前研究的主要内容是（） A.器官移植 B.人类辅助生殖技术 C.安乐死问

下列关于动物在自然界中的作用叙述，不正确的是（　　）

A．动物在生态平衡中起着重要作用

B．动物能促进生态系统中的物质循环

C．动物的数量越多，对植物的生长越有利

D．动物能帮助植物传粉、传播种子，有利于植物的繁殖

如图所示，三个同心圆是同一个点电荷周围的三个等势面，已知这三个圆的半径成等差数列．A、B、C分别是这三个等势面上的点，且这三点在同一条电场线上．A、C两点的电势依次为φ_A=10V和φ_C=2V，则B点的电势是（　　）

A．一定等于6V

B．一定低于6V

C．一定高于6V

D．无法确定

The doctor said I was over-weight. If only I _____ less!

A．ate

B．have been eating

C．have eaten

D．had eaten

Traditional Internet access methods like dial-up were so slow that host computers were connected to the dial-up （71） at the customer premise over slow （72） ports.PPP was designed to run directly over these serial links. But with the advent of broadband Internet（73） technologies such as ADSL and cable modems there has been a considerable increase in the bandwidth delivered to the end users. This means that the host computers at the customer premise connect to the （74） or cable "modem" over a much faster medium such as Ethernet. It also means that multiple （75） can connect to the Internet through the sameconnection.

A．access

B． cache

C．cast

D．storage

治疗早期鼻-鼻旁窦恶性肿瘤的首选方法是（）

A.化学治疗

B.放射治疗

C.手术治疗

D.免疫治疗

E.以上都不是