_____is known to us all is that the old scientist, for____ life was hard in the past,still works very hard in his eighties.

A．As; whom

B．What; whom

C．It; whose

D．As; whose

北京见证了中国历史的沧桑巨变。2008年8月8日北京奥运会开幕前夕，曾出现过上万北京市民排队购买奥运会门票的盛况。那么，1949年居住在北京的居民可能经历的是[ ]

A．英法联军烧杀抢掠

B．康、梁组织公车上书

C．慈禧太后仓皇出逃

D．开国大典