如何使用R删除字符串中其他两个重复出现的字符之间的所有字符？

Question

The following code successfully gets me the text I need before using gsub to help "clean."

am1<-getURL("url.com")
ami1<-htmlTreeParse(am1, useInternalNodes = TRUE)
ami1.tree.parse<- unlist(xpathApply(ami1, path = '//td', fun = xmlValue))
ami1.txt<-NULL
  for (i in 2:(length(ami1.tree.parse)-1)) {
    ami1.txt<-paste(ami1.txt, as.character(ami1.tree.parse[i]), sep = ' ')
  }

The Issue

I'm not being able to delete the entirety of questions within the interview text. For example, the text looks like:

[1] "Q. How well do you think things are going in your marriage?JOE SMITH: It's going quite alright.Q. Where do you see yourself in five years?JOE SMITH: I'll probably move to Los Angeles and get into acting.Q. Okay. How do you think your wife feels about your thinking?JOE SMITH: I think she'd respond positively."

And for formatting's sake:

"Q. How well do you think things are going in your marriage?JOE SMITH: It's going quite alright.Q. Where do you see yourself in five years?JOE SMITH: I'll probably move to Los Angeles and get into acting.Q. Okay. How do you think your wife feels about your thinking?JOE SMITH: I think she'd respond positively."

To be absolutely clear, what I need from the text above is:

[1] "It's going quite alright. I'll probably move to Los Angeles and get into acting. I think she'd respond positively."

"It's going quite alright. I'll probably move to Los Angeles and get into acting. I think she'd respond positively."

I've tried:

 ami1.txt<-gsub("Q.[^?]+H:", "",ami1.txt)
 ami1.txt<-gsub("Q.[^?]+H: ", "",ami1.txt)
 ami1.txt<-gsub("Q.*H:", "",ami1.txt)

It comes down to me not grasping regex surely, but I'd greatly appreciate if someone could point me in the right direction.

Alas I've lied, the text is apparently a tad more complicated. I've added the more complicated element to the end of the above text, below. Some "questions" (Q.) start with a sentence:

 str2<-"Q. How well do you think things are going in your marriage?JOE SMITH: It's going quite alright.Q. Where do you see yourself in five years?JOE SMITH: I'll probably move to Los Angeles and get into acting.Q. Okay. How do you think your wife feels about your thinking?JOE SMITH: I think she'd respond positively.Q. That's interesting. When would you consider speaking to her?JOE SMITH: Probably, tomorrow. Q. That sounds good. How do you feel now? Better than before?JOE SMITH: Yeah I'm feeling alright."

Q. How well do you think things are going in your marriage?JOE SMITH: It's going quite alright.Q. Where do you see yourself in five years?JOE SMITH: I'll probably move to Los Angeles and get into acting.Q. Okay. How do you think your wife feels about your thinking?JOE SMITH: I think she'd respond positively.Q. That's interesting. When would you consider speaking to her?JOE SMITH: Probably, tomorrow. Q. That sounds good. How do you feel now? Better than before?JOE SMITH: Yeah I'm feeling alright.

Task remains the same, and akrun's answer gets me close:

 trimws(gsub("Q[^?]+\\?|[A-Z ]+:", "", str2))
 print(str2)
 [1] "It's going quite alright. I'll probably move to Los Angeles and get into acting. I think she'd respond positively. Probably, tomorrow.  Better than before? Yeah I'm feeling alright."

[1] "It's going quite alright. I'll probably move to Los Angeles and get into acting. I think she'd respond positively. Probably, tomorrow. Better than before? Yeah I'm feeling alright."

Final Update

Akrun's answer:

 trimws(gsub("Q[^?]+\\?|[A-Z ]+:", "", str2))

I'm not totally sure why the above answer wasn't fully deleting everything in between the "Q" and last question mark, but alas. After the revisions to my question above, I figured what I was actually looking for was for everything from "Q" to the ":" to be deleted. So I used this tool to help me understand what was wrong with my understanding of regex. I got to the following to wipe out all characters in between "Q" and the ":".

 gsub("Q[^:]+\\?|[A-Z ]+:", "", str2)

Answer 1

We could match the characters that start with Q followed by characters that are not a ? ( [^?] ) followed by a question mark or ( | ) upper case letters followed by a : and replace it with blanks. If there are leading/lagging spaces, use trimws

trimws(gsub("Q[^?]+\\?|[A-Z ]+:", "", str1))
#[1] "It's going quite alright. I'll probably move to Los Angeles and get into acting. I think she'd respond positively."

data

str1 <- "Q. How well do you think things are going in your marriage?JOE SMITH: It's going quite alright.Q. Where do you see yourself in five years?JOE SMITH: I'll probably move to Los Angeles and get into acting.Q. Okay. How do you think your wife feels about your thinking?JOE SMITH: I think she'd respond positively."