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:The history of the volcano has been identified with the early Pliocene age . Sentence 2:However , the caldera of the volcano is dated to a comparatively recent history of 8000 years .
however

Sentence 1:Akane is able to extract the part , and she and Yukari earn the respect of the Atlantis crew . Sentence 2:But the Orpheus launches due to a testing fault , and ends up in a very deep orbit , unable to begin its mission .
but

Sentence 1:In terms of the measurement of wafers and flat panels , it is very important to place the sensor chip precisely and without any contact along the surface . Sentence 2:Therefore , the chip is integrated directly into the bearing 's surface .

therefore