英文完形填空 in the summer ,paper cups for drinks are everywhere.b

英文完形填空 in the summer ,paper cups for drinks are everywhere.but be careful ,because some
paper cups might be b() for your health.
a new set of national standards for paper cups will c() out on 7.1.most cups we use now would not m() them,said dongjinshi,executive vice-president of international food packaging association in beijing.according to the new standard,recycled materials are not allowed any m().also,cuos must not b() too soft .cuos that are unusually white may be d() because they may contain some chemicals that are bad for your health.the standards also set r()for patterns on paper cups.coloured patterns cannot be w()1.5cm of the top and 1cm of the bottom.
it is easy for people to take the ink i()their bodies while d()fif the pattern is too close to the top,said dong.
hnsqwhj 1年前 已收到1个回答 举报

mexxc 幼苗

共回答了17个问题采纳率:88.2% 举报

取AB重点F
连接EF ED
则有EF∥ AB∥CD
所以∠BAE=∠FEA (内错角)
FE垂直平分AB所以∠AEF=∠FED
又因为EC=CD所以∠DEC=∠EDC
∠EDC=∠FED(内错角)=∠BAE
即∠AEC=∠FEA+∠FED+∠DEC=3∠BAE

1年前

8
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