数据的逻辑结构有线性结构和______两大类。
参考答案：非线性结构
1989年联合国大会通过的《儿童权利公约》的核心精神是__________。
Yan Zi and Zheng Jie of China ________the Women’s doubles trophy(奖杯)after winning the final at the Australian Open tennis tournament in Melbourne January 27，2006.
A．held
B．were holding
C．are holding
D．had held
