As a saying goes, the wise man knows he knows nothing, _________ the fool thinks he knows all.
—Don’t hesitate to buy the dress if you like the design and pattern.—No, I won’t, the price is reasonable.
I am delighted as chairman of the students,union last winter.
The beautiful sunset our attention,and we stopped to watch it.
We're still at the airport. If it weren’t for the delayed flight, we _____the concert right now.
It never occurred to humans until the mid-l990s some animals can be cloned.