下列关于黄土高原的地表特征,描述正确的是[ ]
A.起伏和缓、开阔坦荡
B.山水环绕、沃野千里
C.沟壑纵横、地面破碎
D.雪山连绵、冰川广布
答案:C
——Why are the housing prices in big cities going up all the time?
————One reason is that people are__________ into overcrowded cities in great numbers.
A.breaking
B.filling
C.pouring
D.hurrying
百日咳病人进行隔离,至痉挛性咳嗽出现后隔离()天。
A、10
B、20
C、30
D、40