请根据句意从方框中选择合适的动词，并用其适当时态填空，使句子通顺。

____ It was raining heavily when he ________ home last night.
____ Mary wonders what she _________ as when she grows up.
____ — Amy, I called you yesterday evening, but nobody answered the phone.— Oh, I ________ a walk with my mother at that time.
____ —________ you ________ a letter to your mother recently?—Yes, I wrote one last Sunday.
____ We are told that sound ___________ through air at a speed of about 340 metres per second.