The headmaster went to Washington ______ the first time last September.

单项选择题—______your step ,Jim, or you might fall into the water. —Oh,dear! Look where I am going.

单项选择题Does ______ matter if he can't finish the job on time

单项选择题Since our knowledge is ______ none of us can exclude the possibility of being wrong.

单项选择题Who wrote The American

单项选择题Does the TV say ______ happened in Iraq every day