问题
选择题
“The impact will only grow Iran’s leaders decide to change course and meet their international obligations,” US Secretary of State Clinton warned．
A．in case that
B．provided that
C．unless
D．until
答案
答案：C
这题考查连词的用法：A． in case that以防，B． provided that 条件是，C.unless 除非D． until直到。句意是：美国国务卿希拉里警告说：“影响会持续增长，除非伊朗领导人改变做法，履行他们的国际义务”，所以选C。