That is why there is no floor four in some buildings and hotels, for example. Often a number 8 is added in front of the 4 for hotel rooms on the fourth floor. 这就是为什么...
∪: union of 并,合集 “A∪B”读作:the union of A and B 33 ∩: intersection of 交,通集 “A∩B”读作:The intersection of A and B 34 ∫: the integral of ……的积分 “∫x”读作...
The number of Japanese tourists who travelled abroad increased dramatically from just under 5 million to around 15 million between 1985 and 1995, a rise of about 10 million...
更多内容请点击：过年千万别送这10种礼物