问题
.Hawking became world-famous in _______.
A:his thirties in the 1970’s
B:the thirties in his 1970
C:his 30s in 1970’s
D:the thirties during the 1970
B:the thirties in his 1970
C:his 30s in 1970’s
D:the thirties during the 1970
正确答案是：
