【評論主題】The internet service provider requests that subscribers _________ certain that their systems are pro

【評論內容】request that subscribers (should).....看完整詳解

【評論主題】The internet service provider requests that subscribers _________ certain that their systems are pro

【評論內容】request that subscribers (should) + Vr原形動詞should 被省略掉了，所以後面一定要接原形動詞