Why do animals of different species communicate with one another?
A. Because they like to set up their own communication systems.
Because they want to take advantage of the other species.
C. Because they tend to keep more food to themselves.
D. Because they benefit from using the information from other species.
查看答案
谐振状态下电源供给电路的功率全部消耗在电阻上。()
在正弦交流电路中,当发生串联谐振时,电感和电容上的电压可能会高于电源电压许多倍,因此串联谐振又被称为电压谐振。()
茶文化
"你要茶还是咖啡?"是用餐人常被问到的问题,许多西方人会选咖啡,而中国人则会选茶,相传,中国的一位帝王于五千年前发现了茶,并用来治病,在明清(the qing dynasties)期间,茶馆遍布全国,饮茶在六世纪传到日本,但直到18世纪才传到欧美,如今,茶是世界上最流行的饮料(beverage)之一,茶是中国的瑰宝。也是中国传统和文化的重要组成部分。