【题目】Churchill once warned Hitler, “If you dare to invade Britain, you ____ pay for it with great cost.”
A.will
B.shall
C.may
D.should

【答案】B
【解析】句意：丘吉尔警告希特勒：如果你胆敢侵犯不列颠，你一定会为此付出巨大代价的。shall用于二三人称表示警告、命令、威胁等，题干中是警告。故选B。