1. But investigators were not satisfied with the answer: they still did not know what agent brought plasmodium to human beings.
    但是调查者对答案并不满意：他们仍不知道是什么媒介物把疟原虫带给了人类。

2. What then was the malaria-transmitting agent?
    那么，传染疟疾的中介又是什么呢？

3. Albert did not fit the description of any secret agent Charles had ever read about.
    艾伯特一点也不像查尔斯读过的书里描写的特工。

4. “You are disappointed,” Albert said over his shoulder. “You were told that I was a secret agent, a spy, dealing in secrets and danger.
    "你一定很失望，" 艾伯特转过头来说道。"有人告诉你我是个特工，一个间谍，总是做秘密情报和危险的买卖。

5. I also know a real estate agent who can help you find a house or an apartment.
    我也认识一位房地产经纪人, 他也可以帮助你找一间房子或公寓.