Помогите пожалуйста с решением

Form one sentence of the given two using the following model.
Model: This mistake is gross. That mistake is not so gross.
That mistake is not so gross as this one.
1. These apples are tasty. Those apples are not so tasty.
2. The Volga is long. The Don is not so long. 3. My house is tall. Your house is not so tall. 4. Tom's pronunciation is good.
Your pronunciation is worse. 5. The winter in Moscow is cold.
The winter in London is not so cold. 6. Your mother is young.
My mother is not so young.