【单选题】听力原文:This is the California Broadcasting Station. Now here is the whether forecast. The California Weather Station announced at five o'clock this afternoon the weather forecast for the next 24 hours: ...
【单选题】The Development of Rubber Here is the story of rubber. From the earliest time it was common knowledge(51)the Peruvians that when a cut was made in the outside skin of a rubber tree, a white liquid(52)...