【单选题】I really don’t know _____ to do .
【单选题】I really don’t know I had this photo taken.
【简答题】材料的定额耗量是由净用量和 两部分组成。
【单选题】--- I think the environment is becoming worse and worse. --- Yes, I really don’t know we can do about it.
【单选题】______ I really don’t like art, I find his work impressive.