在磨光金属基底冠的过程中,如不慎使冠边缘过薄,技术员用普通瓷粉堆筑,烧烤后金瓷冠最易出现下列哪项问题?( )
A campus emergency ______ occur at any time of the day or night, weekend, or holiday, with little or no warning.
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