2. 外语
  3. According to the passage, people started to make glass ______. According to the passage the new telephone communication system

According to the passage, people started to make glass ______. According to the passage the new telephone communication system

admin2009-04-15  67
问题 According to the passage, people started to make glass ______.
According to the passage the new telephone communication system ______.
选项 A、has been put into actual use
B、was put into actual use in 1977
C、was put on experiment in 1977
D、had been repeatedly experimented on before 1977
答案D
解析 由文章第三段可以得知，1977年人们试验成功，因此试验应该是在1977年之前就已经开始进行了的。
转载请注明原文地址:https://kaotiyun.com/show/K58d777K
本试题收录于： 公共英语二级笔试题库公共英语（PETS）分类
0

公共英语二级笔试

公共英语（PETS）

相关试题推荐
随机试题
最新回复(0)