问题补充:
both sides accept these terms will everlasting peace be established in this region.
A. Unless
B. As long as
C. If only
D. Only if
答案:
A. Unless
B. As long as
C. If only
(答案→)D. Only if
解析:句意:只有双方都接受了这些条款,这个地区才能建立永久的和平。A. Unless除非;B. As long as只要; C. If only要是……改多好啊,后常用虚拟语气; D. Only if只要,后用部分倒装。题干是部分倒装结构,而选项中只有only if位于句首时,才可用部分倒装结构。故选D。