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【单选题】
贵州盛产金银花，金银花中能提取出绿原酸（结构如图所示），绿原酸有很高的药用价值．下列说法正确的是（ ）A.
绿原酸甲酯的分子式为C 16 H 18 O 9
B.
绿原酸在氢氧化钠的醇溶液和加热的条件下可以发生消去反应
C.
与1mol绿原酸分别反应，最多各消耗KOH、Na、Na 2 CO 3 、NaHCO 3 的物质的量之比为4：6：3：1
D.
绿原酸水解的一种产物R遇到FeBr 3 不显色，比R少4个氧原子的L分子能和碳酸钠反应产生二氧化碳，则L分子的同分异构体有10个
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举一反三
【单选题】将/tmp目录下名字以file字样打头，紧跟一个除0-9之间的数字之外的任意字符，以.txt结尾的所有文件打包为一个叫做file.tar 的文件,下面哪些命令是正确的？
A.
tar -cf file.tar /tmp/file[!0-9].txt
B.
find /tmp -name "file[!0-9].txt" -exec tar -uf ./file.tar {} \;
C.
find /tmp -name "file[!0-9].txt" -exec tar -cf ./file.tar {} \;
D.
tar -czf file.tar /tmp/file[!0-9].txt
【多选题】将/tmp目录下名字以file字样打头,紧跟一个除0-9之间的数字之外的任意字符,以.txt结尾的所有文件打包为一个叫做file.tar 的文件,下面哪些命令是正确的?
A.
tar -cf file.tar /tmp/file[!0-9].txt
B.
tar -uf file.tar /tmp/file[!0-9].txt
C.
tar -uf file.tar /tmp/file![0-9].txt
D.
tar -cf file.tar /tmp/file[!N].txt
【单选题】—Spacecraft 'Discovery' has failed in the course of launch. —_____? They have been preparing for the test. [ ]
A.
How come
B.
When
C.
How
D.
Why not
【简答题】 将tmp目录下名字以file字样打头,紧跟一个除0-9之间的数字之外的任意字符,以.txt结尾的所有文件打包为一个叫做file.tar 的文件(提示,结合tar命令)
【单选题】According to the passage, why was John Glenn's flight considered so successful?
A.
It was the first time a rocket had reached orbit and returned.
B.
NASA had finally learned how to stay in orbit for a long time.
C.
The astronauts were able to move outside the spacecraft.
D.
He was able to land on the Moon's surface for the first tim
【单选题】Andy was crying in his room just now，but he wouldn’t tell me_______ made him so sad.
A.
why it was that
B.
why was it that
C.
what it was that
D.
what was it that
【单选题】将 /tmp 目录下名字以 file 字样打头,紧跟一个除 0-9 之间的数字之外的任意字符,以 .txt 结尾的所有文件打包为一个叫做 file.tar 的文件 , 下面哪些命令是正确的?
A.
tar -cf file.tar /tmp/file[!0-9].txt
B.
find /tmp -name "file[!0-9].txt" -exec tar -uf ./file.tar {} \;
C.
tar -czf file.tar /tmp/file[!0-9].txt
D.
find /tmp -name "file[!0-9].txt" -exec tar -cf ./file.tar {} \;
【单选题】将/tmp目录下名字以file字样打头，紧跟一个除0-9之间的数字之外的任意字符，以.txt结尾的所有文件打包为一个叫做file.tar 的文件,下面哪些命令是正确的？
A.
tar -cf file.tar /tmp/file[!0-9].txt
B.
find /tmp -name "file[!0-9].txt" -exec tar -cf ./file.tar {} \;
C.
find /tmp -name "file[!0-9].txt" -exec tar -uf ./file.tar {} \;
D.
tar -czf file.tar /tmp/file[!0-9].txt
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