To answer the first part of your question, I'd like to say that our studies were very extensive.
你问题的第一部分,我要说的就是我们的研究非常广泛。
I had forgotten all about the snails when Robert suddenly said that I must stay to dinner.
我把蜗牛的事已忘得一干二净,罗伯特突然提出一定要我留下来吃晚饭,这才提醒了我。