新西兰英语 386 More flooding in Queensland, Australia

（单词翻译）

　　The flooding in Queensland has now reached Brisbane. Some of the towns north of Brisbane, which had the earlier floods, have become flooded again.
This time the Brisbane River has already flooded its banks. Workers in the central city were told not to go to work. Many businesses have closed. Electricity has been cut off in some places because of the danger when water mixes with electricity. Queensland premier¹, Anna Bligh, told residents² they should stay home and not travel. Many roads are covered with water and are not safe. However, if people live in areas which could flood, it would be a good idea to stay with friends or family who live on the hills in Brisbane.
We have seen frightening pictures of rivers in flood, sweeping³ cars and boats downstream, out of control. Even houses have moved in the flood waters. People sitting on the roof of their house or on the roof of their car have been rescued. But not everybody has been rescued. So far 10 people have died. Police are looking for another 90 people.
Yesterday, the rain continued making it difficult for helicopters⁴ to search for people who needed help. Today, it is a beautiful day, hard to believe that the rivers are still rising because of the rain in the past few days.
The Brisbane River could rise to more than 5m tomorrow morning at high tide. After that, it may take a week for the river level to drop.
New Zealand has sent a team of 15 Civil Defence⁵ volunteers to help, and will also send a Red Cross team. Australia always helps New Zealand when we need it.
Questions
Present perfect tense is used to show an event that started in the past and continues right now. How many examples of present perfect tense can you find? Is it possible to replace these verbs⁶ with the simple past tense? Has the meaning changed?