现代操作系统中最基本的两个特征是( )。A．并发和不确定 B．并发和共享 C．共享

Last evening, I went to teahouse with my best friend Susan. Before the tea was serving, we talked to each other happily. When the waiter went to us with the tea, we didn’t see him. Unfortunately, Susan rose her hand to comb her hair just while the waiter bent to put the plate on the table. His hand hit the cup, and the tea was spattered (溅) on her trousers. In my surprise, instead of complaining , Susan smiled, “ So lucky that it’s not on my shirt, and I can’t even clean it.” Her words were very inspired. We can’t foresee what will happen, but looking at it in a positive way can make us be happy

我国水资源的时间分布规律是

A．冬春多，夏秋少

B．冬春少，夏秋多

C．春夏多，秋冬少

D．春夏少，秋冬多

外资企业的外国投资者以工业产权、专有技术作价出资时，其作价金额不得超过外资企业注册资本的( )%。

A．5

B．10

C．15

D．20

在对会计报表整体已经发表了否定意见或无法表示意见后，如会计报表某组成部分构成会计报表整体的主要部分，注册会计师不应再对该组成部分出具审计报告。( )

单向通道保护环适用于（）型业务。

A.集中型

B.分散型

C.接入网

D.以上3种