题目

Toronto, Canada, is a fantastic city. It’s large, has many job opportunities, and most importantly, it is open and tolerant(包容的). It is one of the most diverse(多样的)cities in the world, with over 140 languages spoken there. What’s more, 12.5 percent of the city’s population is Chinese.With all these different groups, it’s no surprise that you can find food from all over the world, from Vietnamese to Ethiopian. Many of these restaurants are located in the Kensington Market area, where there’s also music to hear and art to see.This diversity is probably the reason why people在食物链草→鼠→狐中，若消灭了全部的狐，鼠的数量会（　　）A. 缓慢上升 B. 迅速上升 C. 仍保持相对稳定 D. 先上升后下降