With summer ing on, the weather gets hot .
A. day after day
B. day and night
C. day in and day out
D. day by day
网友回答
A. day after day
B. day and night
C. day in and day out
(答案→)D. day by day
解析： 本题是词语的辨析。day by day意为“天天”，强调事物的不断更新，day after day也为“一天天”，但强调事物的重复或反复。