(Blank)
The AI has learned / learned new words today.
Has learned
Engineers have been testing / tested the robot all morning.
Have been testing
The program had already crashed / already crashed before the update.
Had already crashed
Before the update, the chatbot had given/had been giving wrong answers all day
Has been giving
The AI has improved/has been improving its answers since this morning.
has been improving
The AI system __________ (not / make) any mistakes yet.
has not made
Developers __________ (train) the model since last month.
have been training
By the time the user logged in, the app __________ (update).
had updated
This robot __________ (learn) from its errors for years.
has been learning
The engineer was tired because he __________ (debug) the code all night.
had been debugging
The AI ______ its database since this morning.
A) has improved
B) has been improving
C) improved
D) had improved
C-Has been improving
By the time the system crashed, it ______ millions of calculations.
A) has completed
B) has been completing
C) had completed
D) had been completing
C-had completed
The chatbot ______ all the user questions today.
A) has been answering
B) has answered
C) answered
D) had answered
B-Has answered
The robot looks tired because it ______ simulations all night.
A) has run
B) had run
C) had been running
D) has been running
B-Had run
Since last week, the developers ______ the new AI module.
A) have been testing
B) have tested
C) tested
D) had tested
A-Have been testing
By the time the presentation started, the AI __________ (crash).
had crashed
The robot behaved unpredictably during the experiment because it ______ (receive) multiple streams of incorrect data for several hours.
had been receiving
The users were confused after noticing that the AI system ______ (change) its responses multiple times while processing thousands of queries.
had been changing
By the time the major update arrived, the AI system ______ already ______ (learn) all the old user patterns and had started predicting potential errors.
had learned
The AI assistant started giving more accurate and personalized responses because it ______ (analyze) the detailed user behavior data continuously over the past six months.
had been analyzing
The system failed because it had received corrupted input all night.
“all night” = duration → should be had been receiving (Past Perfect Continuous)
By the time the server crashed, the system had been processing millions of requests.
Correct
The developers have been testing the app since last week.
Correct
The AI has improved its performance since this morning.
Not Correct
since this morning” → ongoing action → we need Present Perfect Continuous
The chatbot has answered all user questions today.
“today” = unfinished time period → Present Perfect Simple is fine