6.4349精确到0.01的近似数是( )精确到个位的近似数是( ),保留4个有效数字时是( ),精确到千分位时是( )。
6.43 , 6, 6.435, 6.435
Putting a candle in the window ___ a traditional practice in many cultures, ____ has a variety of meanings in the United States.
A.was; that
B.is; it
C.has been; which
D.had been; which
教育研究的最高水平是()
A.直觉观察水平
B.探究研究水平
C.迁移推广水平
D.理论研究水平