In the box below, write a topicalising phrase that will link the new sentence with 'given' information already mentioned in earlier sentences. Then, click 'check' to compare your answer with the model.
Chromatography is a technique for separating the components of a mixture based on adsorption differences
between the components. The most sophisticated methods include gas chromatography and high performance liquid chromatography.
, invisible components such as gases and colourless liquids
can also be separated out of the mixture.