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:The 4.7 cm armor - piercing shell ( Pz.Gr. 36 ( t ) ) will not penetrate a Mk. II at 600 to 800 metres ( 660 to 870 yd ) . Sentence 2:But the crew will abandon the tank because fragments spall off the armor on the inside .

but