压力表是指示容器内介质压力的仪表,是压力容器的重要安全装置,压力容器广泛采用的是各种类型的______压力计。
A.液柱式 B.活塞式C.弹性元件式 D.电量式
参考答案:C
We stayed in a quiet hotel,__ _.
A.next to it was a thick wood
B.next to which was a thick wood
C.next to it there was a thick wood
D.next to which a thick wood was
第二信使cAMP的作用是激活
A.DNA酶
B.磷酸化酶
C.蛋白激酶
D.腺苷酸环化酶
E.磷酸二酯酶