dressed up 打扮 play a trick on 捉弄,取笑 have fun with 和...一起玩的开心 have taken place 发生 look forward to 期盼 will be covered with 被...覆盖 in memory of 为纪念 day and night 日日夜夜 belief 信念,意见 arrival 到达
(x-1)^2 -4
15 5+1x10=15
看
1、有理数的乘法法则:两数相乘,同号得正,异号得负,并把绝对值相乘。 2、正,负,绝对值相乘 3、积仍为0