Mei Li:
What is featured on the central yellow stripe of the flag of Ghana??
Shuai Zheng:
black star
Mei Li:
What stretch of water was used as practice by the Dambusters in preparation for the attack on the Ruhr??
Shuai Zheng:
derwent water
Mei Li:
A polygraph is more commonly known by what name??
Shuai Zheng:
lie detector