1. What is the price of these white shoes?

2. Why don't we cycle to school?

    What about cycling to school?

3. Mai's shirt is the most expensive

    My shirt is the cheapest

1. How much are these white shoes ?

=> What is the price of these white shoes ?

- What is the price of : hỏi về giá tiền

2. Let's cycle to school in order to keep our environment less polluted.

=> Why don't we cycle to school in order to keep our environment less polluted.

=> What about cycling to school in order to keep our environment less polluted.

- let's + Vinf = Why don't we + Vinf = What about + Ving 

- in order to + Vinf : để mà -> chỉ mục đích 

3. My shirt is 10 bảng . Mai's shirt is 20 bảng

⇒ Mai's shirt is more expensive than my shirt.

⇒ My shirt is cheaper than Mai's shirt.