Ⅰ.单项填空(共15小题；每小题1分，满分15分)
请认真阅读下面各题，从题中所给的A、B、C、D四个选项中，选出可以填入空白处的最佳选项。
1．(2015·常州一中高三模拟)Practice is the only ________ to testify truth, while learning of theory eventually serves practical application.
A．evidence B．element C．criterion D．contrast
2．(2015·无锡高三模拟)Under the Dome, funded by Chai Jing, was released on Feb. 28th, ________ has raised the public’s awareness about air pollution.
A．which B．that C．who D．what
