计算。

3×4＋3=____  5×5－15=____  3×3＋20=____

    There will be many changes in our life in the future. We will____ flying cars to work. We will travel to ____ . Maybe we will ____ live in space. Students won't ____  schoolbags to go to school any more. They will learn on ____ at home. And there will be robots in our home. The robots will help us do all the housework. Life will be great at that time.

下列关于细胞中化合物的叙述，不正确的是（　　）