用括号内所给动词的适当形式填空，必要时可加助动词或情态动词。
Once upon a time, a very old man named
Yu Gong lived near two mountains. They were so high and big that it {#blank#}1{#/blank#}(take) a long time to walk to the other side.
The old man told his family that they should all help him to move the mountains.
But his wife said an old man probably even{#blank#}2{#/blank#}(not move) a small tree and where they would
put all the earth and stone from the mountains. Yu Gong said they could put it into
the sea because it's big enough {#blank#}3{#/blank#}(hold) everything. So they all started
digging the next day and moved some of the earth and stone to the sea.
One day, a man saw Yu Gong and his
children when they {#blank#}4{#/blank#}(work) on
moving the mountains. He told Yu Gong that he could never do it because he was old
and weak. As soon as the man finished {#blank#}5{#/blank#}(talk), Yu Gong said that his family could
continue to move the mountains after he died because his family would live and grow,
but the mountains could not get bigger. So Yu Gong and his family kept on {#blank#}6{#/blank#}(dig) day after day and year after year.
Finally, a god was so moved by Yu Gong that he sent two gods to take the mountains
away. This story reminds us that you can never know what's possible unless you try
to make it {#blank#}7{#/blank#}(happen).
