--How long has Robert _______? ---Since 2000.
If you buy ________ iphone 6 in our store, you can get _____umbrella for free.
---It will be my turn. I feel a bit nervous.---________. You can make it.
The population of China is _________ than that of Australia.
You don't know __________________________.
—He hardly spent any time on his subjects, _________?—_________, so he does badly in his lessons.