Select the most appropriate option to fill in blank number 2.
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. may.
- May is used in the present tense to indicate that something is likely to happen but with a hint of uncertainty.
- Here, "may" refers to the possibility that saliva can help neutralise acidity in the mouth and throat.
- The other option means:
- Shall show determination concerning future tense.
- Could is used in the past tense to express general possibility.
- Need to isn't appropriate as there is no obligation that the saliva will perform that function.