TASK DEFINITION: In this task, you're given a sentence and your task is to generate a simplified sentence that focuses on lexical paraphrasing from the original sentence given in the input.
PROBLEM: he was a leading figure in the german political party alliance ' 90 / the greens , and according to opinion polls , he was the most popular politician in germany for most of the government 's duration.

SOLUTION: he was a main figure in the german political party alliance ' 90 / the greens , and according to opinion polls , he was the most popular politician in germany for most of the government 's time in power.

PROBLEM: economy the only economic activity of importance is agriculture.

SOLUTION: the only important economic activity is agriculture.

PROBLEM: command module pilot stuart roosa took several hundred seeds on the mission , many of which were germinated on return resulting in the so called moon trees.

SOLUTION:
command module pilot stuart roosa took several hundred seeds on the mission , many of which were germinated upon his return , resulting in what has become known as moon trees.