有理数$\frac{1}{2}$的相反数是       (    )

我国加入世界贸易组织的时间是（　　）

①中国特色社会主义理论体系是把握社会主义先进文化前进方向的根本指针

②中国特色社会主义理论体系是社会主义先进文化发展和创新的源泉

③中国特色社会主义理论体系能够指导我国社会主义先进文化建设

④中国特色社会主义理论体系是引领社会思潮的旗帜、抵制各种错误思想的武器

    Mr. White lives in the countryside with his wife, Mrs. White. From Monday to Friday he works in a small office near his house. He is free on Saturdays and Sundays. He has a nice garden near his house. He likes growing flowers and he usually works in the garden on Saturdays and Sundays. The flowers are colourful and beautiful. Mrs. White likes them very much. She often helps Mr. White. They live happily together.