多选题Which of the following fragments might cause errors？（）AString s = Gone with the wind；String t = good ；String k = s + t；BString s = Gone with the wind；String t；t = s[3] + one；CString s = Gone with the wind；String standard = s.toUpperCase（）；DString s =
题目
多选题
Which of the following fragments might cause errors？（）
A
String s = Gone with the wind；String t = good ；String k = s + t；
B
String s = Gone with the wind；String t；t = s[3] + one；
C
String s = Gone with the wind；String standard = s.toUpperCase（）；
D
String s = home directory；String t = s - directory；