They became so addicted to food that they ate everything they saw.
could
Although the microphone stopped working, the singer continued the performance.
managed to / was able to
The student was very nervous at the exam and didn’t relax.
couldn't / wasn't able to / didn't manage to
With more practice, he ____ do a split.
will be able to
I'm not sure, but it's possible I'll answer better next time.
might be able
When she was a student, she had a skill to solve equations very quickly.
could / was able to
After several attempts, the writer finally finished the chapter.
managed to
After the surgery, he ____ see again.
could / was able to