You are allowed to use on the test the official version of the Periodic Table of the Elements which most of you should have by now.
在测试中你们可以使用,化学元素周期表的官方版本,你们应该大部分都有了吧。
They had a mail service, although it was for official use only.
建立了邮政系统,虽然只供官方使用。
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