渐减曝气是将空气量沿曝气池廊道的流向逐渐增大，使池中的氧均匀分布。
参考答案：错
Look at the factory! It _______ before I came here. [ ]
A. is built
B. has built
C. was built
D. was building
哪些品德在安拉跟前最贵？
