佝偻病时可见的胸廓改变是（）
A．鸡胸
B．扁平胸
C．桶状胸
D．气胸
E．肺气肿
参考答案：A
每一轿厢地坎下应装设护脚板，护脚板的垂直高度应不小于（）m。
A.0.5
B.0.75
C.1.00
D.1.50
Mother wanted to be a good provider, a role she _______ since her marriage to Father.
A．shoulders
B．has been shouldering
C．is shouldering
D．shouldered
