Tina’ssisterbegantorideabiketoschool

問題詳情：

Tina’s sister began to ride a bike to school ___________.

A. when 6 years old the age of 6 C. at the age of 6 years D. at 6 years old

【回答】

B

知識點：介詞和介詞短語

題型：選擇題