Hi,<br/><br/><b>In</b> replacing the faucet washers, he felt he was making his contribution to the environment.<br/><br/><b>By</b> replacing the faucet washers, he felt he was making his contribution to the environment.<br/><br/>Can they mean the same things? <br/><br/>You think you can make me feel better <b>by </b>bribing me with money? Or<br/><br/>You think you can make me feel better <b>in </b>bribing me with money? <br/><br/>Are both prepositions used properly? <br/><br/>Thanks for correcting!