下列有关世界五大车展，说法正确的是（）。A.巴黎车展以其“中立”身份赢得最为“公平”

下列( )不是导致市场失灵的原因。

A．外部性以及公 * * 品

B．非对称信息

C．气候变异

D．垄断的存在

HBsAg

A．只出现在乙肝患者的血清中
B．阳性者不能做献血员
C．具有抗原性，其相应抗体可作为早期诊断的依据
D．只存在Dane颗粒表面
E．阳性者可以输血

在考生文件夹下有一个数据库文件“samp3.mdb”，里面存在设计好的窗体对象“fs”。请在此基础上按照下面的要求补充窗体设计。

在窗体的页眉节区中添加一个标签控件，名称为“bTitle”，标题为“学生基本信息输出”。

Some spiders hunt on the ground, others build webs to trap their food, but the grass water spider catches its prey by running along the surface of the water.
This special water spider lives on the grassy banks of streams where mosquitoes, damsel flies and other insects come to feed and breed.
Although it is one of the largest spiders in New Zealand, it has an unusual ability. It doesn’t disturb the water as it waits for its meal, and there is barely a ripple when it skims across the surface at lightning speed to catch its prey.
Grass water spiders deal swiftly with larger insects like damsel flies by pulling their heads under the water and holding them there until they drown.
After a meal, the grass water spider spends up to half an hour grooming itself. It wipes its eight eyes, brushes its antennae, and takes special care to clean the hairs on its body.
It is the hairs that trap tiny bubbles of air so that the spider can run down a blade of grass and stay underwater for up to an hour when it is frightened. The hairs also keep the spider dry, even underwater.
It is only when the female spider is caring for the young that she does not hunt on the water. After mating, she produces a large egg sac, which she carries around for five weeks. Once the eggs start to hatch, she attaches the sac to some blades of grass or a thistle. She then tears the sac open and releases the tiny spiders into the nursery web.

How does the grass water spider kill its prey

A. In a web



B. By drowning
C. By poisoning


D. With its antennae

[案例]

[背景材料1]
某桥梁工地，桥面离地面高28m。采用满堂脚手架现浇箱梁。施工前，项目部拟招聘部分工人，经过体检，发现部分患病人员，分别患有：心脏病、精神病、恐高症、癫痫病、严重贫血病、严重关节炎、皮肤病等。
进行桥面施工时，为了方便施工，现场工人移动了部分安全防护设施和安全警示标识牌。施工完毕后，需拆除支架。
问题：

该桥桥面施工前，其满堂脚手架需要由( )进行单项设计。

A．专业技术人员
B．包工头
C．项目负责人
D．班组长