舒张早期奔马律的组成的是 ()
A.S3与S1、S2
B.病理S3与S1、S2
C.S4与S1、S2
D.病理S4与S1、S3
E.S4与S2、S3
参考答案:B
阿司匹林发挥作用,抑制的酶是
A.磷脂酶A2
B.二氢叶酸合成酶
C.环氧酶
D.过氧化物酶
E.胆碱酯酶
A double male coupling is one that().
A.has left hand twist
B.has inside threads on both ends
C.has outside threads on both ends
D.takes two men to operate