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 sifter is used for separating mixtures. 
Sentence2: a sifter is used for some recipes.

SOLUTION: sifter

PROBLEM: Sentence1: Ribosomes are structures in the cytoplasm where proteins are made. 
Sentence2: prokaryotes can make proteins.

SOLUTION: made

PROBLEM: Sentence1: Brakes are also involved when the vehicle is on an incline. 
Sentence2: friction is used to stop a vehicle on an incline.

SOLUTION:
incline