香港和澳门都很重要的经济支柱是
[ ]
A.对外贸易
B.博彩业
C.旅游业
D.金融业
答案:C
______ I was surprised at ______ her positive attitude towards life after losing her legs.
A.How, is
B.That, was
C.What, were
D.What, was
通气/血流比值(ventilation/perfusion ratio)