如图所示的电路中,电源电压U=3V,R1=2ΩM闭合开关后,电流表读数为0.5A,求:
Every year, tourists from home and abroad visit places of interest, taste delicious food and enjoy ____ (they)in Taizhou.
某小组将调查到的生物进行了分类,他们将鲫鱼、水草、水鸭、蟹等归为一类,而将松、蝇、玫瑰、麻雀等归为一类。他们是按照什么归类的:( )