Problem: Wwo sentences:
They also said the rule will make the nation 's electrical system more reliable -- a high-profile issue after last week 's massive power blackout .
They also said the rule will improve the reliability of the nation 's electrical system , which is needed after last week 's massive power blackout .
Do they have the same meaning?

Answer: yes

Problem: Wwo sentences:
Tehran has said it will only sign the protocol if a ban on imports of peaceful Western nuclear technology is lifted .
Tehran has made clear it will only sign the Additional Protocol introducing such inspections if a ban on the import of civilian Western nuclear technology is lifted .
Do they have the same meaning?

Answer: yes

Problem: Wwo sentences:
In the first stage of the attack , the Lovsan worm began fouling computers around the world .
The first stage of the malicious software began Monday , when the Lovsan worm began spreading around the world .
Do they have the same meaning?

Answer: yes

Problem: Wwo sentences:
Scholars in medical ethics have said the issue of medicating patients to improve their mental health to execute them might present formidable obstacles for doctors .
Scholars in medical ethics have said the notion of medicating people to improve their mental health to the point where they may be executed can present formidable obstacles for doctors .
Do they have the same meaning?

Answer:
yes