法洛四联症病儿蹲踞舒适的原因是
A.心脑供血增加
B.肺静脉回心血量增加
C.增加体循环阻力,减少右向左分流,增加肺血量
D.缓解漏斗部痉挛
E.以上均不是
参考答案:C
---You are great! Congratulations on winning the first prize!
---Thank you! Mr. Yu You__________ me to practice again and again every day.
A.enjoyed
B.complained
C.encouraged .
D.celebrated
大理石板块面层板块间隙宽度允许偏差为( )。
A.0.5mm
B.1.0mm
C.1.5mm
D.2.0mm