To enter Class B airspace, such as an approach to a major metropolitan airport, an explicit ATC clearance is required.

需要持有明确的空中交通管制许可才能进入B类空域，如接近一个大都会机场。

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For gastric antrum carcinoma, the operation should include subtotal gastrectomy, clearance of group 1, 7, 8, 9, 12 lymph nodes, resection of omentum major and minor.

胃窦癌可行胃大部切除，但廓清淋巴结需包括第1、7、8、9组和第12组，整个清扫面应至大小网膜外。

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For gastric antrum carcinoma, the operation should include subtotal gastrectomy, clearance of group 1, 7, 8, 9, 12 lymph nodes, resection of omentum major and minor.

胃窦癌可行胃大部切除，但廓清淋巴结需包括第1、7、8、9组和第12组，整个清扫面应至大小网膜外。

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