业主公约签订的条件是小区入住率达( )以上,已入住业主中持有产权达( )以上。
A.30%,30%
B.30%,50%
C.50%,50%
D.50%,80%
参考答案:B
甲种酒精含纯酒精40%,乙种酒精含纯酒精36%,丙种酒精含纯酒精35%。将这三种酒精混合在一起得到含纯酒精38.5%的酒精11千克,已知乙种酒精比丙种酒精多3千克。那么甲种酒精有多少千克
A.4
B.5
C.6
D.7
After the examination, Tom said that the long cold winter was at last _____. [ ]
A. in the end
B. by the end
C. at an end
D. at the end