あの・あれ・～ということ(言及する人や物を限定する)

that with a ....

It was (that with a) heart united we overcame difficulties and reached the peak of Everest together.

overcome   /,əƱvər'kʌm/　v)乗り越える･克服する

★ overcome something     to succeed in dealing with or controlling a problem that has been preventing you form achieving something

difficulty   /'dɪfɪkəlti/　n)困難･苦労

★ a problem; a thing or situation that causes problems