我国科学家屠呦呦因为“发现青蒿素—— 一种用于治疗疟疾的特效药”而获拉斯克奖。青蒿素化学式为C₁₅H₂₂O₅，下列关于青蒿素的说法正确的是（        ）

点M（4，2）关于x轴对称的点的坐标是（　　）

Tony loves exciting things. He trekked        the forests by himself last summer．    

    It is the last day of June today. It is Grandma's birthday. Father, mother and I go to see her.

    She lives(居住) with my uncle in a village(村子). Early in the morning we buy a birthday cake and some fruit and go to her home by bus.

    Grandma and uncle are very happy to see us. We give presents(礼物)to Grandma and say “Happy birthday to you!” She is very happy. Then we sit down to talk. Uncle goes to prepare(准备)lunch. The meal( 餐) is very nice. We all like it very much. At 4 o'clock, we say goodbye and go back home.