Until now the only aircraft which have been available for the Airborne Early Warning (AEW) role have been large, complex and extremely expensive systems such as the Boeing E3A Sentry and the Grumman E2C Hawkeye.是什么意思_Until now the only aircraft which have been available for the Airborne Early Warning (AEW) role have been large, complex and extremely expensive systems such as the Boeing E3A Sentry and the Grumman E2C Hawkeye.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句