题目内容：
在1977年，中国进出口总额还不到150亿美元，仅占世界贸易总额的0.6%。A. In 1977, the total sum of Chinese imports and exports was less than $15 billion, put China’s share of world trade at 0.6 percent.
B. In 1977, the sum total of Chinese imports and exports was less than $15 billion, putting China’s share of world trade at 0.6 percent.
C. In 1977, the sum total of Chinese imports and exports was less than $150 billion, putting China’s share of world trade at 0.6 percent.
D. In 1977, the total sum of Chinese imports and exports was less than $150 billion, putting China’s share of world trade at 0.6 percent.
参考答案：