单项选择题A．separate itB．use 3-D techC．put something in itD．remove something from it

单项选择题A．openB．happyC．self-protectedD．humble

单项选择题What is the character of British labor force

单项选择题Who is famous for his historical novel of Rob Roy

单项选择题If the distribution of a construction is functionally equivalent to that of one or more of its constituents, the construction is called______.