a new study suggests that children who often get serious ear infections are twice as likely to become overweight later in life than kids with healthier ears.
여기서 as가 무슨역할을 하는건지 모르겟어요 ㅠ

the rest of the body seems to have been covered in much shorter feathers를
it seems that the rest of the baby was covered in much shorter feathers.
로 바꿀때 동사가 왜 과거시제로 바뀌는지 이해가 안되요.

the salmonberry라는 주어의 동사는 is 인데, the salmonberry는 a salmonverry 가 아니니까 are 이라고 생각하면 안되는건가요?

people ages 18 to 24 talk on their cell phones more than any other age group.
groups 가 아닌이유를 모르겟어요

부탁드려요~