under的同类词有哪些

根据题意，单词under的同类词语有in，on等等。因为under是一个介词，on，in也是介词。例如，his father is drawing a picture under the big tree.他的爸爸在这棵大树底下画画。

my sister is on the bed because she has a cold.我的妹妹在床上，因为她感冒了。