透平油主要作用？
参考答案：
润滑、散热、液压操作。
机组轴承润滑及散热；给调速器及各液压操作阀等提供操作用油。
—Would you love to hang out with us, Helen?
—Sorry. I would rather _____ at home than _____ out with you. [ ]
A. to stay; hang
B. stay; hang
C. stay; hanging
D. to stay; to hang
香蕉皮上面生有黑斑，还能吃么？
