机械加压送风的防烟楼梯间的余压应为（）Pa。（易）
A、20-30
B、30-40
C、40-50
D、50-60
参考答案：C
企业采用融资租赁方式租入的固定资产，应在租赁期开始日，将租赁开始日租赁资产公允价值与最低租赁付款额现值两者中较高者，加上初始直接费用，作为租入资产的入账价值。（）
The concentration of a certain chemical in a full water tank depends on the depth of the water. At a depth that is x feet below the top of the tank, the concentration is 3
parts per million，where 0＜x＜4. To the nearest 0.1 foot, at what depth is the concentration equal to 6 parts per million
parts per million，where 0＜x＜4. To the nearest 0.1 foot, at what depth is the concentration equal to 6 parts per million