This study shows that language may differ，the order in which young kids learn the parts of

This study shows that language may differ，the order in which young kids learn the parts of speech appears to be the same across different languages.
A. since
B. so
C. while
D. but

A. sinceB. soC. whileD. but解析：连词辨析。A既然，自从；B于是；C当…时；尽管；然而；D但是；句意：研究发现，尽管学习的语言不一样，但是在所有不同的语言中孩子学习的顺序都是一样的。根据句意说明本句中的while是指“尽管”，表示上下文的转折关系。故C正确。

这个答案应该是对的