内容摘要：He said: "It's something that we've entered in the past but this year we are lucky enough to be selected and to be performing at one of the most major rock and metal festivals in the country and probably the world."

He said: "It's something that we've entered in the past but this year we are lucky enough to be selected and to be performing at one of the most major rock and metal festivals in the country and probably the world."

That order remained in place during President Joe Biden's term. Washington never clarified what constitutes "ties" to the military, so many students had theiror were turned away at US borders, sometimes without a proper explanation.

One of them, who did not wish to be named, said his visa was cancelled by Customs and Border Protection (CBP) when he landed in Boston in August 2023.He had been accepted into a post-doctoral program at Harvard University. He was going to study regenerative medicine with a focus on breast cancer, and had done his master's degree from a military-affiliated research institution in China.He said he was not a member of the Communist Party and his research had nothing to do with the military.

"They asked me what the relationship was between my research and China's defence affairs," he told the BBC then. "I said, how could breast cancer have anything to do with national defence? If you know, please tell me."He believes he never stood a chance because the officials had already made up their minds. He recalled one of them asking: "Did Xi Jinping buy your suitcase for you?"

What was surprising, or even shocking then, slowly turned normal as more and more Chinese students struggled to secure visas or admissions to study science and technology in US universities.

Mr Cao, a psychology major whose research involves neuroscience, has spent the past school year applying for PhD programs in the US.In an operation said to have taken 18 months to prepare, scores of small drones were smuggled into Russia, stored in special compartments aboard freight trucks, driven to at least four separate locations, thousands of miles apart, and launched remotely towards nearby airbases.

"No intelligence operation in the world has done anything like this before," defence analyst Serhii Kuzan told Ukrainian TV."These strategic bombers are capable of launching long-range strikes against us," he said. "There are only 120 of them and we struck 40. That's an incredible figure."

It is hard to assess the damage, but Ukrainian military blogger Oleksandr Kovalenko says that even if the bombers, and command and control aircraft were not destroyed, the impact is enormous."The extent of the damage is such that the Russian military-industrial complex, in its current state, is unlikely to be able to restore them in the near future," he wrote on his Telegram channel.