Given the task definition and input, reply with output. 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:Once the required temperature has been achieved , the mould opens and an array of pins , sleeves , strippers , etc. are driven forward to demould the article . Sentence 2:Then , the mould closes and the process is repeated .
then