a yet unfinished task的用法和样例：
- The thought of the unfinished task weighed heavily on my mind.
- We shall complete the unfinished task of reunification left to us by our predecessors.
- John explained away his unfinished task by showing his boss a certificate for sick leave.
- Unfortunately, Chen Ruiduan passed away from a liver cancer in 2007, but the unfinished task was taken over by his daughter - Chen Lifei.