at – of– tag –

at the - - - of at the age of 〜歳の時に at the beginning of 〜の初めに at the end of 〜の終わりに at the top of 〜の頂上で at the foot of 〜のふもとに at the bottom of 〜の底に at the back of 〜の後ろに at the forefront of 〜の最前線に...