搜题请搜索小程序“爱下问搜题”
问题 选择题

下列对应关系不正确的是（　　）

A．煤气中毒----CO引起

B．Al（OH）3----治疗胃酸过多

C．H2作燃料----可燃性

D．纯碱----属于碱

答案

A、煤气的主要成分是一氧化碳，一氧化碳有毒，所以煤气中毒主要有一氧化碳引起，正确；

B、氢氧化铝可与酸反应，所以可用来治疗胃酸过多，正确；

C、氢气具有可燃性，所以可作燃料，正确；

D、纯碱是碳酸钠，碳酸钠由钠元素和酸根组成；而碱是由金属元素和氢氧根组成，所以碳酸钠不是碱，是盐，故错误；

故选D．

单项选择题

In the following essay, each blank has four choices. Choose the best answer and write down on the answer sheet.

In low - speed network, it is usually adequate to wait for congestion to occur and then react to it by telling the source of packets to slow down. In high - speed networks, this approach often works poorly, because in the (1) between sending the notification and notification arriving at the source, thousands of additional (2) may arrive. In ATM network, a major tool for preventing (3) is (4) control. When a host wants a new virtual (5) , it must describe the traffic to be offered and the service expected.

4（）

A．flow

B．admission

C．traffic

D．time
查看答案
单项选择题

亚砷酸主要的药理作用是

A．杀菌作用

B．抑菌作用

C．收缩毛细血管

D．对细胞原生质有毒性作用

E．抗免疫作用
查看答案