【单选题】American geneticists George W. Beadle (1903-1989) and Edward L. Tatum (1909-1975) proposed a molecular definition of a gene based on their mutation studies in spores of fungi in _____: a gene is a seg...
【单选题】听力原文:W: Can I help you? M: Yes, I'd like to read some articles that are on reserve about British culture. W: Professor Grand's class? M: That's right. How could you know? W: Let's just say you are not...
A.
That the library opens at 8:00.
B.
That no one else has read the articles.
C.
That none of the material he needs is available.
D.
That reserve materials can be taken out of the library.