漢字は練習すれ___するほど、覚えられます。
Q. Which completes 'the more you practice, the more you remember'?
Translation
The more you practice kanji, the better you remember them.
Explanation
The pattern is ば-form + same verb + ほど: 練習すれば練習するほど 'the more you practice...'. Only ば works in this fixed construction.