题目

单词拼写 根据句意及首字母和括号内汉语提示，写出单词完成下列句子 76. She spent years            (观察)and recording their daily activities. 77. To make members of a team perform better, the trainer first of all has to know their _____________(强项) and weaknesses.  78. It’s bad _________(礼貌）to talk with your mouth full .                                                           79. She stepped back appearing surprised and put up her hands, as if in     （防御） 80. It3．点O为直线AB上一点，在直线AB上侧任作一个∠COD，使得∠COD=90°．（1）如图1，过点O作射线OE，当OE恰好为∠AOD的角平分线时，请直接写出∠BOD与∠COE之间的倍数关系，即∠BOD=2∠COE（填一个数字）；（2）如图2，过点O作射线OE，当OC恰好为∠AOE的角平分线时，另作射线OF，使得OF平分∠COD，求∠FOB+∠EOC的度数；（3）在（2）的条件下，若∠EOC=3∠EOF，求∠AOE的度数．