如图,在宽为20m、长为30m的矩形地面上修建两条同样宽的道路,余下部分作为耕地.若耕地面积需要551m2,则修建的路宽应为( )
A:1 m
B:1.5 m
C:2 m
D:2.5 m
果树开花季节,果园里放养蜜蜂的目的是( )
This is 3-D printer. And this is an artificial (人工的) ear. Can you believe that scientists printed this artificial ear by this 3-D printer?
①食物多样,粗细搭配
②多吃鱼肉,少食果蔬
③肉鱼蛋类,必须新鲜
④变质剩饭,喂养禽畜
⑤“虫眼蔬菜”,放心食用
⑥每日三餐,按时进食,