请找出每个小题中不属于同一类的选项,并将字母标号填写在题前括号内。
( ) 1. A. Social StudiesB. homeworkC. Moral Education D. P. E.
( ) 2. A. youngB. shortC. quietD. thin
( ) 3. A. fruitB. grapeC. appleD. orange
( ) 4. A. mountainB. skyC. airD. healthy
( ) 5. A. closetB. pathC. mirrorD. end table