The king is said to _______ by the spider weaving its web in the cave where he was hiding and defeated his enemy at last.

A．be encouraged

B．being encouraged

C．have been encouraged

D．have encouraged

按我国卫生标准规定，焊接过程中产生的有毒气体氮氧化物的最高允许浓度为（）毫克/立方米。

A.0.1

B.0.5

C.1

D.5