One of the earliest known birds with a beak and contour feathers, Confuciusornis sanctus, with large clawlike "thumbs" on its wings, which probably helped them to climb up to a launching position for flight. A) with large clawlike "thumbs" on its wings, which probably helped them to (B) with large clawlike "thumbs" on their wings, which probably helped it to (C) had large clawlike "thumbs" on its wings, which probably helped them (D) had large clawlike "thumbs" on its wings, probably to help it (E) had large clawlike "thumbs" on their wings, probably to help it 排除ab,不用with, 因为是one of用单数,排除c,e gmat里很喜欢用probably 然后加表目的的不定式 |