热水采暖系统入口装置主要由调压装置、关断阀、除污器、压力表、温度计等组成。当供热系统不大时,可采用的调节装置是()。
A.截止阀
B.调压板
C.闸阀
D.蝶阀
参考答案:A, B
读图,回答下列问题。
(1)A、C两地年降水量较多的是_______,原因是_________________________________。
(2)A、B、C三地气温最低的是________,原因是_________________________________。
(3)若此图位于地中海沿岸,则此时为_______季,A、B、C三地气温年内变化最大的是_________。
Can you tell me ______ at that time? [ ]
A. what were they doing
B. what they were doing
C. what are they doing
D. what they are doing