双线站间区间

寒邪的致病特点是（）。

A.其性开泄

B.易伤津血

C.易于动血

D.其性重浊

E.其性凝滞

橡胶属于重要的工业原料。它是一种有机高分子化合物，具有良好的弹性，但强度较差。为了增加某些橡胶制品的强度，加工时往往需进行硫化处理。即将橡胶原料与硫黄在一定条件下反应；橡胶制品硫化程度越高，强度越大，弹性越差。下列橡胶制品中，加工时硫化程度最高的是(　　)

A．橡皮筋

B．汽车外胎

C．普通气球

D．医用乳胶手套

Most animals have little connection with animals of a different kind, unless they hunt them for food. Some­times, however, two kinds of animals come together in a partnership(伙伴关系) which does good to both of them. You may have noticed some birds sitting on the back of sheep. This is not because they want a ride, but because they find easy food in the parasites(寄生虫）on sheep. The sheep allow the birds to do so be­cause they remove the cause of discomfort. So although they can manage without each other, they do better together.

Sometimes an animal has a plant partner. The rela­tionship develops until the two partners cannot do with­out each other. This is so in the corals(珊瑚）of the sea. In their skins they have tiny plants which act as “dustman”, taking some of the waste products from the coral and giving in return oxygen which the animal needs to breathe. If the plants are killed, or are even prevented from light so that they cannot live normally, the corals will die.

小题1:Some birds like to sit on a sheep because _________.

A．they can eat its parasites

B．they consider the sheep as their shelter

C．they enjoy traveling with the sheep

D．they find the position most comfortable小题2:The underlined word “they” in the first paragraph refers to _______.

A．birds and parasites

B．sheep, birds and parasites

C．parasites and sheep

D．birds and sheep小题3:It can be learnt from the text that the coral depends on the plants for ________.

A．comfort

B．light

C．oxygen

D．food小题4:What does the second paragraph mainly discuss?

A．Some plants depend on each other for food.

B．Some animals and plants develop their relationship easily.

C．Some animals and plants depend on each other for existence.

D．Some animals live better together.

流行性角结膜炎的潜伏期一般为()

A．5～7天

B．1～3天

C．3～5天

D．4～6天

E．7～10天

“国共的十年对峙”，这十年是指（）

A.1921~~1931

B.1925~~1935

C.1927~~1937

D.1937~~1947