Could you please check these last two sentences, please? Thank you for your help.

1. Britain entered the First World War in 1914 by declaring war on Germany after the German invasion of Belgium.
Peace was made at Versailles in 1919. Many British war poets expressed their thoughts about the stupidity of war in their poems.
2. Their message, especially that of Wilfred Owen, was That war is an act against God and man.

lower-case "t" on "that" in 2.

Sure, I can check those sentences for you.

1. "Britain entered the First World War in 1914 by declaring war on Germany after the German invasion of Belgium. Peace was made at Versailles in 1919. Many British war poets expressed their thoughts about the stupidity of war in their poems."

This sentence is accurate and provides a concise description of Britain's involvement in the First World War, the peace treaty, and the expression of war's stupidity through poetry by British war poets.

2. "Their message, especially that of Wilfred Owen, was that war is an act against God and man."

This sentence is grammatically correct, but I would suggest adding a comma after "especially" to clarify the sentence's structure. It would look like this: "Their message, especially that of Wilfred Owen, was that war is an act against God and man."

To check the accuracy of these sentences, one can refer to reliable historical sources such as books, articles, or reputable websites about World War I and the British war poets. These sources often provide specific details about Britain's entry into the war, the peace treaty at Versailles, and the themes expressed by poets like Wilfred Owen. Cross-referencing multiple sources can help ensure accurate and well-supported information.