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But the United States had problems with making its first diagnostic kits and initially limited testing only to people who had come from China and displayed symptoms of Covid-19.

But the pandemic made it hard for her company to deliver video materials to foreign clients either through cross-border travel or postal services.

But there have been quite a few external uncertainties, such as cooling global economic growth, turbulent financial markets and fluctuations in commodity prices, said Liu Aihua, an NBS spokeswoman, at a news conference.

But?Walmart’s revenues still pale in comparison on an overall basis: Amazon’s online sales totaled?.8 billion, or more than six times the billion Walmart recorded during the same time periods.

But such tests need to be done with random sampling, ensuring that the people being tested are representative of the geographic, social, racial and other conditions. There are also questions about the accuracy of the blood tests being used. Scientists have found that some of them aren't reliable enough, with too many false positives and false negatives.