All of us found ________difficult to work out the maths problem.
—Are the black shoes ____? —No. It’s ____.
—Does Mary know ____? —Yes, she knows ____.
—Excuse me, is Michael in black pants now? —No. He’s in ____ coat and ____ pants now.
—What does Yang Ping look like? —____
—____ is his car? —It’s black.