As the immune system weakens, it loses the ability ________ illnesses.
The decision was made ________ more medical teams would be sent to help people in the earthquake.
Mobile phone users have developed a series of symbols, such as and to show ________ they feel.
Inside the White House, there is a room called the Oval Office. That's ________ President Obama works.
________ I regret most is that I have promised to make friends with the dishonest girl.
We can find out ________ all the excitement is about by playing QQ's “Happy Farm”.