单阀有何用途？有哪几个作用位置？
参考答案：
单阀用来单独操纵机车的制动、保压或缓解。有单独缓解位、运转位、制动区三个作用位置。
根据语境,填人适当的词语或句子,补全对话
A: It's raining outside, Mary. It's too cold. (1)__________?
B: My hometown is Turpan. It's very hot. The temperature is often over 40℃.
A: (2)__________?
B: I like it in autumn and spring, but I don't like it in winter.
A: Why?
B: The winter in Hangzhou is very rainy. (3)__________.
A: (4)__________?
B: I have lived in Beijing for 3 years. I like summer and autumn, but not spring and winter.
A: (5)__________?
B: Yes, it is very windy and cold.
热值愈高的物质燃烧时，辐射出的热量也愈（）。
A、低
B、少
C、多
D、高
