常见的操作系统包括DOS、OS/2、UNIX、XENIX、Linux、Windows、Netware、Ora-ele等。
A. 对
B. 错
He felt veryembarrassed ______ everyone laughed at his story.
A. as if
B. when
C. if
D. until
Childrendo not necessarily grow sophisticated_____they grow older.
A. as
B. when
C. that
D. while
_______ the teacher told the Fables, thechildren listened attentively and took notes.
As soon as
B. If
C. Whenever
D. While