若某人每次射击击中目标的概率均为$\frac{3}{5}$，此人连续射击三次，至少有两次击中目标的概率为____ 

太阳能路灯的灯杆顶端有太阳能电池板，它能将太阳能转化为电能．并向灯杆下方的蓄电池充电，供夜晚路灯照明．若在一段时间内，太阳光辐射到该太阳能电池板的能量为2.7×10⁷J．这与完全燃烧____kg的煤放出的热量相当；这些能量经转化后，可供功率为35W的路灯工作60h，那么该太阳能路灯的能量转化率是____%．（煤的热值为3.0×10⁷J/kg）

阅读理解。

    Aunt Judy's birthday is coming. She will be 38 years old. Dad and Mum are going to take me to her house. She lives in Guangzhou. We are going to go there by train. Her birthday party will be on Saturday. We are leaving on Friday afternoon. And we are coming back on Sunday evening. I am going to give my dear Aunt Judy a picture . I am drawing it now. I am drawing some beautiful flowers. I am drawing a small dog, too. That's because she likes dogs. The picture will be very nice.