The presence or introduction into the environment of a substance which has a harmful or poisonous effects
The past perfect refers to a time earlier than before now. It is used to make it clear that one event happened before another in the past. It does not matter which event is mentioned first - the tense makes it clear which one happened first.
Answer:
All of the blank spaces need to be filled with “ei”.
Explanation:
ANSWER:
C. If students form a study group, they get better grades.
Voltaire's existence in the wake of death is mind-boggling, his notoriety changing with progressive administrations.
The French revolution thought back to him as a courageous antecedent of its battle, and in 1791, his remaining parts were taken back to Paris and with extraordinary celebration, put in the Panthéon.