骨肉瘤X线征象是()
A.软组织肿胀
B.骨质破坏
C.骨膜反应
D.瘤骨形成
E.以上都是
参考答案:E
.
As I grew up in a small town at the foot of a mountain, the visit to the village_____ scenes of my childhood.
A.came up
B.called up
C.took up
D.made up
简述生物多样性的类型及保护意义。