He whispered to his wife he might wake up the sleeping baby.
A. so that
B. on condition that
C. for fear that
D. so long as
网友回答
A. so that
B. on condition that
(答案→)C. for fear that
D. so long as
解析：根据句意，“他小声地跟妻子说话，惟恐吵醒了孩子。” 空白处应填入“惟恐，以防”，即for fear that。