此题答案为C 吗?-->happyfish0517转移

13: Dolphins lack vocal cords, nevertheless creating sounds: a complicated system of whistles, Squeaks, moans, trills, and clicks are produced by sphincter muscles inside the blowhole.

A: nevertheless creating sounds: a complicated system of whistles, squeaks, moans, trills, and clicks are produced by

B: nevertheless creating sounds: they produce a complicated system of whistles, squeaks, moans, trills, and clicks with

C: but they do create sounds, producing a complicated system of whistles, squeaks, moans, trills, and clicks being produced

D: but they do create sounds, a complicated system of whistles, squeaks, moans, trills, and clicks being produced

E: but nevertheless creating sounds: a complicated system of whistles, squeaks, moans, trills, and clicks produced by

请在标题中注明题号和来源，多谢合作

此题是语法，我帮你转到语法区去~