英语语法分析

As we were enjoying our first mouthful of thermos flask soup, a stout man, opened the gate and came towards us.

当我们享用热水瓶里的第一口汤时，一个胖男人打开大门朝我们走来。

It's handy to have the thermos here.

暖瓶放在这儿好拿。

《新英汉大辞典》

So the thermos is not an open system.

因此热水瓶不是个开系。