3～6个月佝偻病患儿，多见的骨骼系统改变是
A．方颅
B．胸廓畸形
C．手镯、脚镯征
D．颅骨软化
E．下肢畸形
参考答案：D
神经元
How ______ I help you to understand ______ you wouldn’t listen to me?
A．can; when
B．would; because
C．may; if
D．must; when
