tokenize(x, what = "sentence") not working. about quanteda HOT 2 CLOSED

> hardText <- c("will.i.am is a rap name.",  
+               "Mr. Smith goes to Washington, D.C. on the 9.45 train.",
+               "Segmentation is hard etc. etc. for Authors et. al. to get right.",
+               "The U.N. is based in New York.")
> tokenize(hardText, what = "sentence")
[[1]]
[1] "will.i.am is a rap name."

[[2]]
[1] "Mr. Smith goes to Washington, D.C. on the 9.45 train."

[[3]]
[1] "Segmentation is hard etc. etc. for Authors et. al. to get right."

[[4]]
[1] "The U.N. is based in New York."

attr(,"class")
[1] "tokenizedTexts" "list"          
> segment(hardText, what = "sentence")
[[1]]
[1] "will."             "i."                "am is a rap name."

[[2]]
[1] "Mr Smith goes to Washington, D." "C."                              "on the 9.45 train."             

[[3]]
[1] "Segmentation is hard etc." "etc."                      "for Authors et."           "al."                      
[5] "to get right."            

[[4]]
[1] "The U."                "N."                    "is based in New York."