① ∠1 = ∠FEH ;② ∠1 与 ∠2 互补;③若 ∠1=60° ,则 ∠2=120° ;④ ∠1>∠PMF .
18-10(=)8
This book is a little above my head, because there are too many new words in it.
①鲜卑族 ②党项族 ③契丹族 ④女真族