出生后到满1周岁之前称为()
A.胎儿期
B.婴儿期
C.幼儿期
D.学龄前期
E.学龄期
参考答案:B
下列物质按照单质、混合物、氧化物的顺序排列的是( )
A.水银、硬水、水
B.石墨、熟石灰、生石灰
C.氨气、空气、消石灰
D.冰、醋酸、干冰
. ______ understanding the challenges faced by the world’s poorest people can we expect a new future
free of extreme poverty and hunger.
A.On
B.Through
C.Only
D.Only by