Question:
Who was the head of state of People's Republic of China in Dec, 1970?

Context:
 Jiang Zemin is the head of the state of People's Republic of China from Mar, 1993 to Mar, 2003. 
 Ye Jianying is the head of the state of People's Republic of China from Mar, 1978 to Jun, 1983. 
 Soong Ching-ling is the head of the state of People's Republic of China from Oct, 1968 to Jan, 1975. 
 Mao Zedong is the head of the state of People's Republic of China from Oct, 1949 to Apr, 1959. 
 Zhu De is the head of the state of People's Republic of China from Jan, 1975 to Jul, 1976. 
 Li Xiannian is the head of the state of People's Republic of China from Jun, 1983 to Apr, 1988. 
 Yang Shangkun is the head of the state of People's Republic of China from Apr, 1988 to Mar, 1993. 
 Dong Biwu is the head of the state of People's Republic of China from Oct, 1968 to Jan, 1975. 
 Hu Jintao is the head of the state of People's Republic of China from Mar, 2003 to Mar, 2013. 
 Liu Shaoqi is the head of the state of People's Republic of China from Apr, 1959 to Oct, 1968. 
 Xi Jinping is the head of the state of People's Republic of China from Mar, 2013 to Dec, 2022.

Answer:
Soong Ching-ling