TOEFL Listening: TPO-TOEFL听力TPO - F7QF1PFLP51278JDR$

According to the lecture, what are two ways to increase the strength or rope made from Manila hemp fibers? A. Coat the fibers with zinc-based paint B. Combine the fibers into bundles C. Soak bundles of fibers in salt water D. Twist bundles of fibers