城市供热管网地下敷设方式中,()的断面尺寸是依据运行人员能弯腰走路,能进行一般的维修工作的要求定出的。
A.通行地沟
B.半通行地沟
C.无沟敷设
D.不通行地沟
参考答案:B
看图补全对话。
Tom: Hello, this is Tom speaking.
Grandma: Hi, Tom, this is grandma. What is your mother doing?
Tom: My mother is c_____________.
Grandma: What is your father doing?
Tom: My father is s_____________ on the sofa.
Grandma: What are you doing, Tom?
Tom: I am d_____________ my homework.
Grandma: Good boy! What are Peter and Cindy doing?
Tom: Peter is d_____________ on the wall (墙壁) and Cindy is c_____________.
Grandma: Oh, my goodness (天哪)!
电子商务应用框架的自然技术型支柱是()。
A、技术标准
B、政策法律
C、安全认证
D、因特网