People cut down many trees, __________ many animals are losing their homes.
A:so
B:because
C:for
D:or
如图,Rt△ABC中,∠ACB=90°,∠A=20°,△ABC≅△A'B'C,若A'B'恰好经过点B,A'C'交AB于D,则∠BDC的度数为( )
估算.
427×58≈____
60×231≈____
唐朝对外贸易发达,在各国的物产中居唐朝进口首位的是( )
数据:1,2,3,3,4,5的中位数是( )