塔顶负荷大引起的原因是（）。
A.原油性质变轻
B.加工量变大
C.吹汽量大
D.原油组分变重
参考答案：A, B, C
Some people care much about their appearance and always ask if they look fine in ______ they are wearing.
A．that
B．what
C．how
D．which
冒泡排序算法在最好的情况下的元素交换次数为 【1】 。
