他六岁时开始骑自行车.用英语怎么说?
问题描述：
他六岁时开始骑自行车.用英语怎么说?
答
He started to ride bike from six years old
答
He learned to ride bike when he was six.
答
At the beginning of six , he had been ridden the bike .
答
He began to ride bike when he was six。
答
He could ride a bike when he was six.