 It is an application of Machine Learning that firstly uses Feature Selection to automatically extract flu-related terms from Twitter content and then uses those terms to compute a flu-score for several UK regions based on geolocated tweets.
<fluency>  It is an application of Machine Learning that firstly uses Feature Selection to automatically extract flu-related terms from Twitter content and then uses those terms to compute a flu-score for several UK regions based on geolocated tweets.
 It was an application of Machine Learning that firstly uses Feature Selection to automatically extract flu-related terms from Twitter content and then uses those terms to compute a flu-score for several UK regions based on geolocated tweets.