根据句意及首字母或汉语提示完成单词

1. When the traffic light is red, you mustn't c____ the road.

2. I want you to stay here. Don't say g____ to me.

3. The price of the vegetables is really l____, and you may buy some.

4. We should be there by____(正午), shouldn't we?

5. Those who are waiting to buy the tickets are all football ________(狂热者).

同学们积极参加学校少年宫活动．其中参加机器人小组的有18人，航空模型小组的人数比机器人小组的3倍少12人，七巧板科技小组的人数正好是航空模型小组的3倍．参加七巧板科技小组的一共有多少人？