It was not until Mum agreed to buy him a puter, was his favorite, the boy promised to study hard.
A. that; that
B. which; that
C. that; which
D. which; which
网友回答
A. that; that
(答案→)B. which; that
C. that; which
D. which; which
解析：考查强调句型和定语从句。第一空which指代puter 在句中作主语；第二空that与 it was构成强调句型。故B正确。句意：直到妈妈同意给他买他最喜欢的电脑的时候，那个男孩答应认真学习。