指出下列“之”字用法与其他三句不同的一项[ ]
A．面刺寡人之过
B．公与之乘
C．操蛇之神闻之
D．故克之
答案：A
They are putting too much carbon dioxide into the atmosphere, ______ prevents heat from escaping from the earth into space.
A．what
B．that
C．which
D．who
20G的含碳量近似为（）。
A.20%
B.2%
C.0.2%
D.0.02%
