It takes ____ one hour ____ his homework.
A:he; do
B:him; do
C:him; to do
D:his; to do
世界上高原面积广大,有“高原大陆”之称的大洲是( )
过春节时,我国海南地区春暖花开,而黑龙江地区却冰天雪地,其主要影响因素为( )