(5分)下图表示在某晴天的上午，将一盆植物的部分枝叶用干燥的透明塑料袋罩住，扎紧袋口并置于阳光下。请回答：

　　(1)一段时间后，塑料袋内壁上会出现小水珠，这是植物__作用的结果。

　　(2)下午打开袋口，迅速将一根带有火星的卫生香伸人袋内，观察到卫生香复燃，说明袋内含有较多的_______ (气体)，该气体是通过_______作用产生的。

(3)傍晚换上黑色不透光的塑料袋罩上，扎紧袋口。第二天打开，迅速伸进一根燃着的火柴棒，结果火柴棒迅速熄灭。若将该袋内的气体通人澄清的石灰水，石灰水变浑浊。说明此时袋内含有较多的__________(气体)，该气体是通过_________作用产生的。

(56) is a one-way function that takes an arbitrarily long piece of plaintext and from it computes a fixed-length bit string.
(57) is a protocol that most USENET machines now use it to allow news articles to propagate from one machine to another over a reliable connection.
(58) is an approach preferred by cable TV providers. In this solution the fiber terminates at an opto-electrical converter and the final segment is a shared coaxial cable.
(59) is a device used to connect two separate network that use different communication protocol.
(60) is a digital-to-digital polar encoding method in which the signal level is always either positive or negative.

A．Router

B．Gateway

C．Bridge

D．hub