______ is surprising to us is that Tom, for ______ English was once boring, can speak English fluently as though he were a native speaker.

A．What; whose

B．What; whom

C．It; whose

D．As; whom

发达国家应该______自己的历史责任和当前人均排放高的现实，严格______《京都议定书》确定的减排目标，继续承担中期大幅量化减排义务。
填入横线部分最恰当的一项是( )。

A．承担 遵守
B．正视 履行
C．重视 遵守
D．直面 履行