单项选择题
Our ancestors celebrated（）birth of（）child by giving away red eggs.
A. /; a B. /; the C. the; a D. the; the
单项选择题 Mr. Green drove slowly on the way home until he reached the high way,（）the speed limit was 60 miles per hour.
单项选择题 The speed at which an animal lives is determined by（）the rate at which it uses oxygen.
单项选择题 In the distance they saw a（）house.
