从所给出的单词中选出合适的完成对话。

supermarket     meat     shopping    rainy    tomatoes

 Tom: Mum, there's no food at home. Let's go ____today.

Mum: But how's the weather?

 Tom: It's a sunny day. It's not____

Mum: OK. Is there any____in the kitchen?

 Tom: No, there isn't.

Mum: Are there any ____or potatoes?

 Tom: There aren't any potatoes but there is only one tomato.

Mum: All right. Let's go to the ____now.

下列对非金属元素（除稀有气体外）的相关判断正确的是（　　）

①非金属元素都是主族元素　②单质在反应中都既能作氧化剂又能作还原剂　③氢化物常温下都是气态，所以都叫气态氢化物　④氧化物常温下都可以与水反应生成酸　⑤非金属元素R所形成的含氧酸盐（M_aRO_b）中的R元素必定呈现正价．

构成一株油菜的结构层次依次是（　　）