闭式供水系统,根据循环水冷却设备的不同可分为以下几种类型()
A.冷却水池
B.水冷器
C.喷水池
D.冷却塔
参考答案:A, C, D
设f(x)是R上的奇函数,g(x)是R上的偶函数,若函数f(x)+g(x)的值域为[1,3),则f(x)-g(x)的值域为______.
—Susan, do you like my skirt?
—Yes, it is very _____. How much does it ______?
A.beautiful; cost
B.beautifully; cost
C.beauty ; spend
D.beautifully ; take.