多项选择题
以下选项中,无法成功写入内容的是 A.
fid = open("test1.txt","ab")
fid.writelines( ['a', 'b', 'c'] )
fid.close() B.
fid = open("test2.txt","w")
fid.writelines( ['a', 'b', 'c'] )
fid.close() C.
fid = open("test3.txt","a")
fid.writelines( ['1', '2', '3'] )
fid.close() D.
fid = open("test4.txt","w")
fid.writelines( [1, 2, 3] )
fid.close()