--- I am going to visit the Shanghai EXPO this summer. Will you come with me?
---- Thanks. I’m afraid lots of people are planning for that. I prefer to stay at home rather than___   _ there.

If you want to see a doctor, you fix a date with him ahead of time. That is common ________ in the USA.

下列四种元素中，单质的氧化性最强的是（   ）

下列关于科学研究和实验方法的叙述，不正确的是

已知某个几何体的三视图如图所示，根据图中标出的尺寸（单位：cm），可得这个几何体的体积是（   ）