TASK DEFINITION: Generate an overlapping word between the given two sentences. When you find the overlapping words, they don't have to match exactly, e.g., "survival" and "survive" are valid overlapping words. Little words like "the" or "of" don't count! You must generate significant words which are not the stop words.
PROBLEM: Sentence1: a tape measure is used to measure length. 
Sentence2: Length The Base unit for length in the metric system is the meter .

SOLUTION: length

PROBLEM: Sentence1: igneous rocks are formed from magma cooling. 
Sentence2: magma solidifies into igneous rocks.

SOLUTION: magma

PROBLEM: Sentence1: Reproduction is by eggs or the birthing of live young. 
Sentence2: the fallopian tubes are used in birthing live young.

SOLUTION:
birthing