清洗换热器时,()板式换热器的排污阀,开启清洗剂泵,()清晰阀。
A.关闭,打开
B.关闭,关闭
C.打开,关闭
D.打开,打开
参考答案:A
I wanted some paper but there was _____ in the house.
A.nothing
B.none
C.no one
D.not one
农村资金互助社以发起方式设立且发起人不少于()人。
A.8
B.10
C.12
D.14