金属制品在流通过程易受到大气、海水、（）等的作用而锈蚀。
A、井水
B、河水
C、温度
D、细菌
参考答案：D
____ enough money, Jim was unable to buy his girl-friend expensive jewellery. [ ]
A. Not to save
B. Not saving
C. Not saved
D. Not having saved
夏季为避免遭受雷击，一定要在高大建筑上安装______．如何防雷再举一例______．
