We work together to achieve our common purpose： ________ world that is safer， cleaner and healthier than ________ one we are living in.

What’s this ______ English —It’s a pencil.

______ do you go online, Kate — Not often, twice a month.

He came all the way to China for learning it better _______ for making money.

Compared with other animals, snakes are believed to be below ____ in intelligence.