什么是坚膜试验？
参考答案：
在规定条件下，将经液相锈蚀试验后认为无锈的钢棒试样浸入蒸馏水中保持至规定时间后，目视钢棒的生锈程度的试验。
After he was knocked down by a bike, he was badly hurt and had to ________to his feet.
[ ]
A. stand
B. struggle
C. run
D. sit
同一单位工程的不连续的幕墙工程可划分为一个检验批。
