解释下列划线字
①而忘操之 ____
②而置之其坐 ____
③遂不得履 ____
④遽契其舟 ____
⑤先自度其足 ____
⑥不亦惑乎 ____
I want to buy _________ piano for my daughter as the birthday gift. She's good at playing ________ piano. What do you think of _________ black one?