Questions 6 and 7 are based on the following news. At the end of the news item, you will be given 20 seconds to answer the questions. Now listen to the news.

Which of the following is the main cause of global warming（）

A．Toastmasters was originally set up to train speaking skills.
B．Toastmasters only accepts prospective professional speakers.
C．Toastmasters accepts members from the general public.
D．Toastmasters is an exclusive dub for professional speakers.