– The East Lake is not far from the Yellow Crane Tower, so you can easily visit _________ in a day. – Fantastic! I can't wait for it.
A:none
B:both
C:all
D:either
白种人在古代主要分布在欧洲,但是到了近代,在北美洲、大洋洲,白种人成为当地的主要居民,造成这种现象最主要原因是