A:referred to
B:were referred
C:he was referred to
D:were referred to
(Ⅱ)利用所学知识以及(Ⅰ)所得等式,化简代数式 m3−n3m2+mn+n2 ÷ m2−n2m2+2mn+n2 .
如图表示人体胸廓容积的变化,到b点时,肺泡内,呼吸道,外界气压的关系是( )
选用所给的单词填空。
cross bridges afraid between leave