单项选择题
A.怀特先生只有一次提到他在非洲的历险。 B.怀特先生完全不谈他在非洲的历险。 C.怀特先生不止一次谈到他在非洲的历险。 D.怀特先生从未提及他在非洲的历险。
A. mustn't have arrived B. shouldn't have arrived C. can't have arrived D. need not have arrived
A. while B. the moment C. suddenly D. once