呕血伴有冷汗、四肢厥冷、心慌、脉搏增快说明出血至少在多少血量以上()。
A.10%
B.15%
C.20%
D.40%
E.30%
参考答案:C
3,4,6,9,( ),18
A.13
B.12
C.11
D.10
--_________ do you improve your listening?
--I improve my listening ________watching English movies.
A.What , by
B.How , by
C.What , with
D.How , with