国际航运业跨国经营
参考答案：
一家航运企业的生产经营活动跨越国界，直接与国际市场（包括商品市场和要素市场）发生联系的行为
.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
