You will be given a definition of a task first, then an example. Follow the example to solve a new instance of the task.
In this task, given a sentence in the English language, your task is to convert it into the Japanese language.

Test subjects will be administered either a placebo or PA-457 that will be taken in combination with the medication they already take.
Solution: 被験者は、彼らがすでに服用している薬剤と一緒に偽薬またはPA-457を与えられる。
Why? The above sentence is correctly translated from English to Japanese.

New input: Olmert is facing challenges by other leaders to take over the prime ministership.
Solution:
「オルメルトは、首相職を引き継ごうとする他のリーダーの挑戦に直面している。」