| 6. | at someone's disposal | available to be used by someone | For this task you have 10 minutes at your disposal. | Zur Verfügung haben. |
| 7. | acid test | A conclusive test of the success or value of something. | The new product’s launch will be the acid test of its success. | Feuerprobe |
| 8. | lose track of | to no longer know what is happening | I tried to follow the conversation, but I lost the track. | Aus den Augen verlieren, den roten Faden verlieren. |
| 9. | back to square one | having to restart due to failure or a flop | The project failed, so we're back to square one. | Wieder am Anfang sein. Neu beginnen müssen. |
| 10. | by the book | doing something formally correct | The officer handled the situation strictly by the book. | Streng nach Vorschrift. |