A:①比②的放大倍数大,③比④放大倍数小
B:把视野里的标本从图中的乙转为丙时,应选用③,同时提升镜筒
C:从图中的乙转为丙,正确调节顺序:转动转换器→调节光圈→移动标本→转动细准焦螺旋
D:若使物像放大倍数最大,甲图中的组合一般是②③⑤
生态系统中能量的源头是( )
请问:此寓言给了我们什么启示
给下列句子排序
____Thank you very much.
____Would you like some chicken?
____No, thanks. I can use chopsticks.
____Dinner's ready! Help yourself.
____Would you like a knife and fork?
____Yes, please.