Vitamin C helps our bodies make a special chemical, which affects our brains, making us feel happy.
A. in all
B. in turn
C. in advance
D. in short
网友回答
A. in all
(答案→)B. in turn
C. in advance
D. in short
解析：词组辨析。In all 总计 in turn 轮流，反作用于 in advance 提前 in short 总之
句意为维他命C可以帮助我们的身体制造出一种特殊的化学物质，反过来可以影响我们的大脑，让我们感到开心。