If you have a speech to give, a test to take or an important meeting, for example, some anxiety will help you focus on the event and make sure you're prepared for it, Barlow said.

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She gave the participants a well-known stress test, called the Trier Social Stress Test, in which they had to give an impromptu speech explaining why they were the best candidate for a job, in front of a stony-faced panel.

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The test of this speech will be whether it makes it easier for David Cameron to live with and survive the issue that has proved more toxic than any other or whether it consumes him as it has his predecessors.

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Before Dreamforce, his big annual conference in December, Benioff spends weeks laboring over his speech, but the real test is when he has ten or so customers come in to critique a rehearsal over pizza and soda.

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"We have taken robust steps to unravel and address the root causes of these crises, but it would appear that there is a systematic effort by insurgents and terrorists to destabilize the Nigerian state and test our collective resolve, " Jonathan said in a televised speech.

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In a wide-ranging speech, she stated that she believed that the US would sign up to the Comprehensive Test Ban Treaty, which forbids the testing of nuclear weapons.

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