【简答题】898×9≈______ 403×6≈______.
【简答题】某种纱线的细度表示为15tex×3,请说出它的含义。
【单选题】()是主要的数据输入区域,由字母键、数字键、符号键以及其它一些特殊控制键组成,这些按键用于输入各种符号。
【单选题】聚己二酰己二胺 ( Polyamide -66, Nylon 66, PA-66 ) 的单体是
【单选题】A clean environment can help the city bid for the Olympics, which will promote its economic development. [ ]
【单选题】. A clean environment can help the city bid for the Olympics, which ______ will promote its economic development.
【多选题】下列聚合物是共聚物( copolymer )的是
A.
氯乙烯-醋酸乙烯共聚物(Ethylene-vinyl acetate copolymer)
B.
聚己二酰己二胺(Polyamide -66,Nylon 66, PA-66)
C.
丁二烯苯乙烯(Polybutadiene-styrene ,PBS)
D.
丁苯橡胶(Polymerized styrene butadiene rubber ,SBR)
【单选题】()是主要的数据输入区域,由字母键、数字键、符号键以及其他一些特殊键组成,这些按键用于输入各种字符。
【单选题】A clean environment can help the city bid for the Olympics, which ________ will promote its economic development.
【单选题】尼龙610(Polyamide610,PA610)的学名( ),单体为( )