Complete the following sentence with a (compound) word derived from the one(s) given in bracket.
The talks between the two presidents had produced（ ）results, but much remained to be done. (fruit)
本题考查常见名词的形容词形式。
由produced和results可知，空缺处应填形容词修饰名词，fruit意为“成果”，其形容词形式是fruitful意为“富有成效的“，符合题意。
句意：两位总统之间的会谈已经取得了富有成效的结果，但仍有很多（问题）亟待商议。