寒冷的冬季，我们能够看到呼出的“白气”，而炎热的夏天却看不到，请解释这是为什么？

句型转换

1.  Jerry is my father,  and Tommy is my uncle.  (合并为一句)

     Jerry ______ Tommy's ______.  

2. They have got two children.  (改为否定句)

    They ______ ______ two children. 

3. My mother has got a sister.  (改为一般疑问句并作肯定回答)

    ______ your mother ______ a sister?

    Yes, ______ ______ .

4. Taotao has got an apple. (用an orange改为选择疑问句)

    ______ Taotao ______ an apple ______ ______ ______ ?

5. Mr.  Green has got four shops in the city. (对划线部分提问)

    ______ ______ shops ______ Mr.  Green got in the city?