In this task, you are given two sentences in the English language (Sentence 1 and Sentence 2). Your task is to identify the connecting word between the two sentences.

Sentence 1:Content is free of charge for professionals and others . Sentence 2:but registration is required .
but

Sentence 1:And no homes should be built where water supply is at critically low levels . Sentence 2:Furthermore , new housing should be located where jobs are , to reduce the carbon footprints and pollution associated with automobile commuting .
furthermore

Sentence 1:This is known as the sidereal month . Sentence 2:However , during one sidereal month , Earth has revolved part way around the Sun , making the average time between one new moon and the next longer than the sidereal month : it is approximately 29.5 days .

however