They were busy------------the meterials they needed. A to collect B to have collected C collecting D to be collecting They were busy------------the meterials they needed. Correct Answer collecting Bissoy MCQ Team Jun 01, 2023 English A ইউনিট Identifying Missing Word জাতীয় কবি কাজী নজরুল ইসলাম বিশ্ববিদ্যালয়