她口角边渐渐的有了笑影，脸上也白胖了。（ ）
A.Little by little the trace of a smile appeared at the corners of her mouth, but her face became whiter and plumper. B.Little by little the trace of a smile appeared at the corners of her mouth, so her face became whiter and plumper. C.Little by little the trace of a smile appeared at the corners of her mouth, while her face became whiter and plumper. D.Little by little the trace of a smile appeared at the corners of her mouth, when her face became whiter and plumper.正确答案C
