分解因式:a2-2a+1=______.
a2-2a+1=a2-2×1×a+12=(a-1)2.
故答案为:(a-1)2.
关于小肠的解剖,叙述错误的是()。
A.分为十二指肠、空肠和回肠
B.空肠一般位于左上腹
C.回肠黏膜皱襞明显,数量多
D.空、回肠之间无明显界限
E.肠梗阻时结肠皱襞水肿可呈“琴键”征
-- Our school basketball team won the game last night.
-- ________ good news!
A.What
B.How a
C.What a
D.How