用适当的介词填空。
1. English is used _____ the native language in Australia.
2. We are native speakers _____ English.
3. A knife is used _____ cutting things.
4. Millions _____ people are learning to speak English in China.
5. Chinese is one _____ the official languages in the United Nations.
6. Spring comes _____ winter.
7. Today some of the mobile phones can be used to take pictures _____ a camera.
8. Thank you _____ coming to see me.
9. First we have to fill _____ a form.
10. 50% of all business deals are made _____ English.