それを試してみてください。
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<title>改行; Umbruch</title>
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<p>TextTextTextTextTextTextTextTextText TextTextTextTextTextTextTextTextText Text Text TextTextTextTextTextTextText TextTextTextTextTextTextTextTextText TextTextTextTextText TextTextTextTextTextTextTextText TextTextTextTextTextTextText TextTextTextTextTextTextTextTextText TextTextTextTextTextText TextTextTextTextTextTextTextTextText TextTextTextTextTextTextText Text: Hier Umbruch mit ENTER! 改行: Enterキーを使用します!</p>
<p>TextTextTextTextTextTextTextTextText TextTextTextTextTextTextTextTextText Text Text TextTextTextTextTextTextText TextTextTextText: Hier Umbruch mit SHIFT ENTER!<br>
TextTextTextTextText TextTextTextTextText TextTextTextTextTextTextTextText TextTextTextTextTextTextText TextTextTextTextTextTextTextTextText TextTextTextTextTextText TextTextTextTextTextTextTextTextText TextTextTextTextTextTextText Text.TextTextTextTextTextTextTextTextText TextTextTextTextTextTextTextTextText: Hier Umbruch mit SHIFT ENTER! 改行: SHIFT + ENTER キーを使用します<br>
Text Text TextTextTextTextTextTextText TextTextTextText TextTextTextTextText TextTextTextTextText TextTextTextTextTextTextTextText TextTextTextTextTextTextText TextTextTextTextTextTextTextTextText TextTextTextTextTextText TextTextTextTextTextTextTextTextText TextTextTextTextTextTextText Text.TextTextTextTextTextTextTextTextText TextTextTextTextTextTextTextTextText Text Text TextTextTextTextTextTextText TextTextTextText
TextTextTextTextText TextTextTextTextText TextTextTextTextTextTextTextText </p>
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Hans-Günter
P.S.
注: 違い 間に <br/> <br>