【单选题】患儿, 2岁,曾多次患肺炎,活动后有气促但无青紫,胸骨左缘第3~4肋间闻及IV级收缩期杂音,肺动脉瓣区第二音亢进,最可能的诊断是
【多选题】Which of the following costs of consignment are fixed? ( )
A.
costs of documentation
C.
costs of customs clearance
【单选题】If marginal costs equal average total costs,
A.
Average fixed costs are rising.
B.
Average total costs are falling.
C.
Average total costs are minimized.
D.
Average total costs are maximized.
【单选题】患儿,2岁,曾多次患肺炎,活动后有气促但无青紫,胸骨左缘第3~4肋间闻及IV级收缩期杂音,肺动脉瓣区第二音亢进,最可能的诊断是