Theweatherissochangeable.Idon'tk?
The weather is so changeae.I don't know______ A.how to wear B.why to wear C.what to wear D.when to wear 为什么
选C. I don't know what to wear. “what to wear”做的I don't know的宾语，“what”做的是“wear”的宾语，因为wear是及物动词，是必须要带宾语的，如：wear a hat/a pair of shoes/glasses。