填空题 《复合题被拆开情况》 Have you ever been to the city of Guangzhou? Guangzhou is located in the south-central part of Guangdong province and is a regional【B1】________in southern China. The city【B2】________foreign trade and business and it hosts China’s largest trade fair. But what has【B3】________me most is its food. There, you can【B4】________real Cantonese cuisine. You may ask what is the best time to visit Guangzhou. I guess spring and autumn are the【B5】________time of the year to visit the region. There is less rain from October to December than in spring.《问题》：【B5】