President Obama held talks with Chinese President Hu Jintao in Beijing, ________ economic recovery, climate change and stopping the spread of nuclear weapons.

You have to explain ____ us the reason _____ your being absent from school yesterday

e picked up a large sum of money by accident, hebattled with his _____ whether he should keep it or return it to the owner

21st Century is ______ a newspaper; it helps us know a lot about the world.

In some ways Tina and Gina are different。—Yes. Tina isn’t so as Gina。