封闭楼梯间的门必须采用乙级防火门。
参考答案:错
-----Look at the sign. It _________ “No smoking”. ----Oh, sorry, I did not see it.
A.says
B.writes
C.shows
D.Appears
在横线上填上“>”“<”或“=”
69800______68900 二亿______20000万
12×20______40×80 274680030______274860030
46×20______1000 1000000______十万.