NO作为信号分子，它能使细胞内的（）分子浓度升高。
A.cAMP
B.cGMP
C.Ca2+
D.DG
E.PKC
参考答案：B
The environmentalist said: “Making money is blameless, but I can't ________ to unnecessary killing of wild animals for that purpose.”
A．subscribe
B．tend
C．oppose
D．suggest
下列物态变化事例中属于放热的是[ ]
A、将水蒸气通入冷凝管中收集蒸馏水
B、冰箱中冷凝剂制冷
C、在衣柜内放“卫生球”防蛀
D、冬天将冻肉放在水中解冻
