A:磁感线是为描述磁体而建立
B:磁感线是为描述磁场而建立
C:条形磁铁周围的磁感线分布均匀
D:U形磁铁周围的磁感线分布均匀
⑴Can we look at the blue jeans?____ A. It's a shirt.
⑵What's this?____ B. They're shorts.
⑶What colour is it?____ C. Here you are.
⑷What are they?____ D. It's yellow.
根据如图回答问题.
(1)图中A→C的过程为____ .
(2)图中A→B的过程为____ .
(3)图中A→D的过程为____ .
(4)图中B、C、D都属于____,因为它们都是由许多____ 相似,____和____ 相同的细胞联合在一起形成的.