曲度不可能变化的是
A．脊柱颈面B．脊柱胸曲C．脊柱腰曲D．脊柱骶曲E．脊柱侧曲
参考答案：D
Quite a few teenagers are used to depending on their parents, so they aren't able to look after ______. [ ]
A. themselves
B. they
C. them
D. themself
专利权
