4. This is the first time my mother has taste a chinese food
⇨ My mother...... haven’t tasted Chinese food before...........................
5. She is smart. She can do the exercise  ( enough)
⇨ ...She is enough to do the exercise..............................

4. My mother have not tasted Chinese food before.
5. She's enough to do the exercise.

4. This is the first time my mother has taste a chinese food
⇨ My mother haven’t tasted Chinese food before.
5. She is smart. She can do the exercise  ( enough)
⇨ She's enough to do the exercise.