If he _____ he will fall I'll.
If he _____ he will fall I'll.
Explanation
The sentence follows the first conditional structure: If + present simple, will + base verb.
"If he smokes, he will fall ill." (Present simple "smokes" is correct.)
The sentence follows the first conditional structure: If + present simple, will + base verb.
"If he smokes, he will fall ill." (Present simple "smokes" is correct.)