根据首字母及句子意思补全单词，使句子意思连贯、语法正确。

1. Look at the sky! The kites are flying so h              that they look like small birds.

2. — Excuse me. How can I get to the post office?

    — Go down this road until you see a tall building. You can't m              it.

3. Mum, I'm h             after a long run. Please give me something to eat.

4. — I advise doing something to relax ourselves after the exams. Do you a              with me?

    — Yes, but how?

5. Most Chinese have three m             a day. They are breakfast, lunch and supper.

公安工作所面临的形势和工作对象的复杂性，决定了公安工作具有

A．危险性

B．复杂性

C．易受腐蚀性

D．艰苦性