A __________ is a structurally independent unit that usually comprises a number of words to form a complete statement, question or command.A __________ may be a noun or a noun phrase in a sentence that usually precedes the predicate.
查看答案
According to para.1, what are the applications of the SW in the border management?
How are the single windows in different regions different from each other? Please guess the reasons for the differences.
What types of single windows are there? What common features do they share?
What does the author think of the definition given by Recommendation 33?