Answer:
Space exploration will lead to increased conflict among nations and should be discouraged.
Explanation:
EXPLAINS, IS
The tour guide EXPLAINS that either candles or a lantern IS used to see into the tomb.
Tour guide is singular. Therefore, verb used must be in singular form.
Lantern is singular and it is the nearest subject of the verb. Thus, the verb must also be in singular form.
I would say I will definitely check reliability and safety.