火的特性是（） A.曲直 B.稼穑 C.从革 D.炎上 E.润下

在复制中维持模板处于单链状态并保护单链完整的蛋白是

气焊和气割都需要用到乙炔。乙炔俗称电石气(化学式为C₂H₂)，是一种无色无味的气体，密度比空气略小，难溶于水。实验室常用块状固体碳化钙与水反应制备乙炔，该反应比二氧化锰催化过氧化氢分解更加剧烈。请回答：

(1)乙炔的物理性质之一是                      ；

(2)图中仪器a的名称是                         ；

(3)从下图选择实验室制备乙炔所用仪器的最佳组合是                  （填序号）。

当自感为2H的线圈通以10A的电流的时候，线圈中储存的磁场能为（）。

A．10J

B．50J

C．100J

D．200J

违反《保险经纪机构监管规定》，涉嫌构成犯罪的，中国保监会应当( )。

A．向公安机关举报
B．向检察院移送
C．向司法机关举报或移送
D．向法院提起诉讼

Our ape-men forefathers had no obvious natural weapons in the struggle for (1) in the open. They had neither the powerful teeth nor the p claws of the big cats. They could not (2) with the bear, whose strength, speed and claws (3) an impressive " small fire" weaponry. They could not even defend themselves (4) running swiftly like the horses, zebras or small animals. If the ape-men had attempted to compete on those terms in the open, they would have been (5) to failure and extinction. But they were (6) with enormous concealed advantages of a kind not possessed by any of their competitors.

In the search (7) the pickings of the forest, the ape-men had (8) efficient stereoscopic vision and a sense of color that the animals of the grasslands did not (9) . The ability to see clearly at close range permitted the ape-men to study practical problems in a way that lay far (10) the reach of the original inhabitants of the grassland. Good long-distance sight was (11) another matter. Lack of long-distance vision had not been a problem for forest-dwelling apes and monkeys because the (12) the viewpoint, the greater the range of sight-so (13) they had had to do was climb a tree. Out in the open, however, this simple solution was not (14) . Climbing a hill would have helped, but in many places the ground was flat. The ape-men (15) the only possible solution. They reared up as high as possible on their hind limbs and began to walk (16) . This vital change of physical position brought about considerable disadvantages. It was extremely unstable and it meant that the already slow ape-men became (17) still. (18) , they persevered and their bone structure gradually became (19) to the new, unstable position that (20) them the name Homo erectus, upright man.

4（）

A.in

B.upon

C.by

D.with