Hawking became world-famous in .his thirties in the 1970’s the thirties in his 1970his 30s

问题补充：

Hawking became world-famous in .

his thirties in the 1970’s

the thirties in his 1970

his 30s in 1970’s

the thirties during the 1970

答案：

解析：选A。in one’s thirties 在某人三十多岁时，in/during the 1970s意思是“在二十世纪七十年代”。