计算机网络由资源子网和通信子网构成，通信子网负责全网中的_________。
参考答案：信息传递
She is a hardworking student, and all her spare time she has ________ staying in the library.
A．spent
B．is spent
C．to spend
D．to be spent
简述对建筑内中庭防火检查的主要内容。
