按可通航内河船舶的吨级，内河航道划分为（）级
A、2
B、3
C、5
D、7
参考答案：D
The old lady likes to spend time indoors, she can comfortably watch televison and read newspapers.
A．when
B．that
C．which
D．where
由婴儿到成人，上颌骨宽度增长约为（）
A.1.0倍
B.1.6倍
C.3.2倍
D.0.8倍
E.2.0倍
