屏蔽防护是指根据不同放射性物品的性质，采用不同材料对射线进行有效阻隔。
参考答案：对
— What do you think of the film Inception (盗梦空间)?
— Just so-so. I don’t think it worth ______ a second time.
A．watching
B．watched
C．to watch
D．being watched
意识的产生是一个纯自然的过程。( )
