The last sentence said it was too dry and needed watering. The watering action happened before Susan said this sentence, and it was over. Susan said, "Have you finished it?" The present perfect tense also emphasizes that it happened in the past and has an impact on the present. So "that soon" is the past tense.

Peter: This is a surprise.

The last sentence said, "It's raining." It means that rain happened in the past and has continued to this day. Peter said it was really a big surprise, meaning rain, so he used the past tense.

Tips for learning mathematics

1, you should be good at thinking when learning mathematics, and the answers you come up with are far more impressive than those others say.

2. Prepare well before class, so that we can better digest and absorb the unknown knowledge points in math class.

3, the mathematical formula must be memorized, and it must be deduced and can be deduced.

4. The most basic thing to learn mathematics well is to master the knowledge points of textbooks and exercises after class.