The Dongying-Hainan airline for about 5 months. I have taken the flights three times.
A:is open
B:has opened
C:has been open
D:has been opened
实验室部分仪器或装置如图所示,请回答下列问题.
①而两狼之并驱如故____
②无丝竹之乱耳____
③不独亲其亲,不独子其子____
④山峦为晴雪所洗____
⑤斟酌损益,进尽忠言____
⑥为所识穷乏者得我与____
河汊纵横交织,湖荡星罗棋布是指( )