多选题Given： 11. 15. Which three EL expressions， inserted at line 15，are valid and evaluate to "3"？（）A${vals.2}B${vals[2]}C${vals.index}D${vals[index]}E${vals}[index]F${vals[vals[index-1]]}
题目
多选题
Given： 11. 15. Which three EL expressions， inserted at line 15，are valid and evaluate to "3"？（）
A
${vals.2}
B
${vals[2]}
C
${vals.index}
D
${vals[index]}
E
${vals}[index]
F
${vals[vals[index-1]]}