【简答题】A.Wet and stormy weather is on the way. B.Fine weather is expected. C.It's going to be cold. D.The rain will continue.
【单选题】晶闸管导通后流过晶闸管的电流决定于()。
【单选题】What is the weather going to be? It's ____________. [ ]
【单选题】How long is this cold weather going to _____.
【简答题】A.Wet and stormy weather is on the way. B.Fine weather is expected. C.It's going to be cold. D.The rain will continue.
【单选题】— How is the weather going to be next week? — It's going to be ______. [ ]
【单选题】晶闸管导通后,通过晶闸管的电流决定于( )。
【单选题】关于酶原,以下的说法哪一项是正确的?
A.
某些酶在最初由细胞合成或分泌时,没有催化活性,但已形成完整的活性中心
B.
酶原激活通常是酶原分子内部某些肽键断裂,但没有肽段从分子上脱落
C.
酶原由细胞合成,并主要在合成它的细胞内发挥其催化作用
【简答题】酶的活性中心是由 在酶分子中的某些区域相互靠近而形成的,酶活性中心内的基团有 和 两类