Nowadays, many people walk to work ________ Copenhagen Conference calling for living a low-carbon lifestyle to cope with global warming.

A clean environment can help the city bid for the Olympics, ________ in turn will promote its economic development

People all over the world are all ______ about the relationship between China and Japan.

Would you like to climb mountains with me this Sunday—I’d love to. But I _______ play table tennis against Class Three.

____ about the man wearing sunglasses during night that he was determined to follow him．