все Present and Past времена. 1) it's very difficult to ... children nowadays .(raise)
2)the changes in the earth's atmosphere ... many changes in the weather .(have caused)
3) they used some cold water to ... the patient ... (cause to regain consciousness)
4) Matthew ... his father to his way of thinking .(has persuaded )
5) the manager ... the subject of redundancy . ( raised)

1) it's very difficult to raise children nowadays.
Explanation: In this sentence, the verb "to raise" is used in the infinitive form to express the action of bringing up or taking care of children. It is difficult for someone to perform this action in the present time.

2) the changes in the earth's atmosphere have caused many changes in the weather.
Explanation: In this sentence, the verb "to cause" is used in the past participle form "caused" to show that the changes in the earth's atmosphere have had a direct impact on the weather in the past. The verb "to have" is used in the present perfect tense to indicate that this cause-effect relationship still holds true in the present.

3) they used some cold water to cause the patient to regain consciousness.
Explanation: In this sentence, the verb "to cause" is used in the infinitive form to indicate the action of making something happen. The phrase "to cause the patient to regain consciousness" means that the cold water was used to make the patient come back to consciousness.

4) Matthew has persuaded his father to his way of thinking.
Explanation: In this sentence, the verb "to persuade" is used in the past participle form "persuaded" to show that Matthew was successful in convincing his father to adopt his point of view. The verb "to have" is used in the present perfect tense to indicate that this action happened in the past and has a relevance to the present.

5) the manager raised the subject of redundancy.
Explanation: In this sentence, the verb "to raise" is used in the past simple tense "raised" to show that the manager brought up or introduced the topic of redundancy. The verb "to raise" here signifies the action of initiating a discussion or making something known.