【单选题】_____________ trees are there in your village? [ ]
【单选题】_____________ people are there in your family? [ ]
【多选题】以下选项中属于主动式保障技术的有( )。
【简答题】在三极管放大电路的三种基本组态中,()带负载的能力最强。
【单选题】—______? —She is twenty.
A.
What’s your grandmother’s age
B.
How old is your brother
C.
How old is your sister
D.
When is your sister’s birthday
【判断题】地源热泵空调系统的工作原理是夏季制冷时,利用地下冷源与冷凝器进行热交换,将冷凝器的热量带走;冬季制热时,利用地下热源与蒸发器进行热交换,将蒸发器的冷量带走,从而实现热泵系统的正常运转。( )