下列说法中，正确的是（ ）
空心金属球重20N，体积为2dm3轻轻放入足够大且装满水的容器内，则金属球受到的浮力 ____ N，从容器中溢出水的质量 ____ kg（g=10N/kg）
—Mrs. Black, I'm afraid that I'll fail the exam.
—________, dear! Take it easy. I'm sure you'll pass it.
Where does your aunt work? ( at a school )
____
