现浇钢筋砼框架柱、梁或砌筑砖柱的脚手架，规定均按（）计算。
A.单排脚手架
B.双排脚手架
C.外墙脚手架
D.内墙脚手架
参考答案：D
下列临床表现中哪项不能用妊娠时正常的心血管功能改变来解释（）
A.心尖区及肺动脉瓣柔和的收缩期杂音
B.心率加速而有心悸感
C.妊娠晚期轻度的气短、气喘
D.下肢水肿，卧床后消退
E.心浊音界轻微扩大
Maria has _____ trouble _____ math, so she often asks her math teacher for help.
A．much; understanding
B．no; with
C．many; understanding
D．not; to understand
