33. I was used to ______ alone, so travelling with friends has been a big adjustment for me to
make.
(A) travelling (B) travel (C) to travel (D) travelled
36. Olive: What’s the biggest source of pollution? You might be surprised at the answer. Penny: Plastic bags? Olive: No, disposable diapers. Penny: But how come they became a source of pollution? Olive: ____________ (A) About forty years ago. (B) They don’t break down easily. (C) Cotton diapers are good for the environment. (D) People are using fewer disposable diapers.