Fill in the missing words.
{"id":22885,"questions":[{"type":"fill-in-blanks","id":"180","dataJson":{"prompt":"Fill in the missing words.","options":{"chlorine":[{"key":"nitrogen","label":"nitrogen","value":"nitrogen"},{"key":"chlorine","label":"chlorine","value":"chlorine"}],"impurities":[{"key":"smell","label":"smell","value":"smell"},{"key":"impurities","label":"impurities","value":"impurities"}],"rivers and lakes":[{"key":"rivers and lakes","label":"rivers and lakes","value":"rivers and lakes"},{"key":"water treatment plants","label":"water treatment plants","value":"water treatment plants"}]},"feedback":"","template":"Most of the water we use comes from {{rivers and lakes}}, so why is it so clean and pure when it flows through the tap? Water treatment plants have to add chemicals like {{chlorine}} to clean it. Chlorine is what gives the water in swimming pools its smell. The water is then filtered to remove any {{impurities}}, making it clean and safer to drink.","question_type":1,"validResponse":{"chlorine":"chlorine","impurities":"impurities","rivers and lakes":"rivers and lakes"},"fileboyImageId":""}}]}
Fill in the missing words.
Select the missing words in the text.