IgE是() A.免疫反应中最早出现的抗体 B.可通过胎盘的抗体 C.介导局部免疫

题型:单项选择题 B型题

问题:

IgE是()

A.免疫反应中最早出现的抗体

B.可通过胎盘的抗体

C.介导局部免疫

D.介导Ⅰ型变态反应

E.B细胞成熟标志

考点:一级建造师公路工程微生物检验技术基础知识模拟试题三
题型:单项选择题 B型题

What do we do when we go camping? First, we work out a plan. We take food, clothing, a knife, and things for cooking and eating. We take things to keep us away from insects (昆虫)and the sun.

Then we put everything into the car and we drive to the woods(森林). We look for a place for campers and we look for a good place for our tent(帐篷). The place should have a lot of moving air. This will keep some insects away. High land with water on both sides of it is good. Then we put up our tent. We put everything into the tent, and we are ready for fun. We can swim in the lake, walk in the woods, climb a mountain, row a boat, or go fishing.

In the evening we come back to the tent, we build a big fire(火), because it can keep the insects away. We sit around the fire and talk. We may tell interesting stories or we may sing songs.

At night we lie down on the grass. We can look up at the stars. It is a busy day, so we try to go to sleep early.

Everything is dark. Everything is quiet. We hope we won’t hear music from the radio in the next tent. We hope it won’t rain.

小题1:Before going to camp we should first ________ .

A.make a plan

B.take some food

C.take things to keep us warm

D.take something for cooking and eating小题2:We go to camp ________ .

A.by bus

B.by car

C.by bike

D.on foot小题3:Campers can take part in _______ activities

A.one or two

B.few

C.many

D.two or three小题4:In the evening we build a fire because _________ .

A.it is cold at night

B.it can keep us warm

C.it can keep the insects away

D.it is dark and quiet小题5:The campers like to ________ at night

A.hear music from the radio

B.go to sleep early

C.have rain

D.be busy

题型:单项选择题 B型题

室温下,不饱和的硝酸钾溶液露置在空气中一段时间后,有少量的固体析出,其中正确的说法是[ ]

A.硝酸钾的溶解度减小

B.硝酸钾的质量分数变小

C.溶质的质量没有变化

D.溶液变成饱和溶液

题型:单项选择题 B型题

1升溶液中含硫酸4.904克,此溶液的物质的量浓度C(1/2H2SO4)是()。

A、0.05mol/Lmg/L

B、0.5mol/L

C、0.1mol/Lmol/L

D、0.01mol/L%

题型:单项选择题 B型题

关系R(A,B,C)和S(C,D,E)进行关系代数运算,下列各关系表达式中成立的是______。

A.π3(R)∪π1(S)
B.πA,B(R)-πC,D,E(S)
C.πA,B(R)><πD,E(S)
D.π2(R)∩π1(S)

题型:单项选择题 B型题

常见的亲电试剂有()。

A、金属

B、无机酸

C、碱

D、卤素

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