by chance, by accident ☊ like: khi không → →
Was machen Sie, wenn Sie nicht gerade arbeiten? ☊ 
Anh / Chị làm gì khi không phải đi làm? ☊ (Lektion 95, Nr. 1461) + adj.: She left the gas on by mistake and the pan boiled dry (= the water boiled until there was none left). ☊ boil ☊
She was disqualified after failing a drugs test. ☊ fail ☊
The sails hung limply in the flat calm (= conditions at sea when there is no wind and the water is completely level). ☊ flat ☊
fold (away/up): The table folds up when not in use. ☊ fold ☊
This is the opportunity he needs to make a fresh start (= to try sth new after not being successful at sth else). ☊ fresh ☊
He was disappointed at not getting the job, but he'll get over it. ☊ get over sth/sb ☊
I felt guilty about not visiting my parents more often. ☊ guilty ☊
If you suspect a gas leak do not strike a match or use electricity. ☊ match ☊
We had reached the point when there was no money left. ☊ point ☊
She slid out while no one was looking. ☊ slide ☊
Life seems so unfair sometimes. ☊ unfair ☊
an unfriendly atmosphere ☊ unfriendly ☊
He was very unlucky not to win. ☊ unlucky ☊
I waited my chance and slipped out when no one was looking. ☊ wait ☊