Tina’s sister began to ride a bike to school ___________.
A. when 6 years old B.at the age of 6 C. at the age of 6 years D. at 6 years old
Tina’s sister began to ride a bike to school ___________.
A. when 6 years old B.at the age of 6 C. at the age of 6 years D. at 6 years old
B