用“who”或“that”填空
(1) The man____  is talking with my mother is my father .
(2) That book is the one____  I bought yesterday .
(3) He is one of the workers ____  been saved in that accident .
(4) They talked of the things and persons ____  they remembered in the factory .
(5) All____  can be done must be done .

求下列图形的周长．

回忆课文《寓言两则》，并回答问题。