先通读下面的短文，掌握其大意，然后从A、B、C、D四个选项中选择可以填入空白处的最佳答案。
Hi, Tony,
How are you? It's great to 1 you. I'm on a trip with my 2. Let me tell you what we are doing 3 the moment.
My father is 4 photos with his new camera (照相机). He's always 5 and it's difficult for 6 to take a holiday. 7 he looks very happy now. My mother 8 getting ready for the picnic (野餐). In a few minutes, we can have our delicious meal. My sister is calling her friend and 9 the warm sun as well. OK. I have to stop (不得不停下来) 10 It's time to have the meal.
Yours,
Mike
表示的粒子：S；④两个铁离子：2Fe3+；⑤导电、导热性最好的金属：Ag；⑥+2价的镁元素：Mg2+．其中正确的有（ ）
