下列不属于物理性消化的是( )
A:牙齿的咀嚼
B:唾液淀粉酶将淀粉转变成麦芽糖
C:胃肠的蠕动
D:胆汁对脂肪的乳化作用
数3.949×105精确到万位约( )
—What time is it? —It's ______ eight o'clock.