－How did it        that the secretary knew where we were?－Maybe he had been following us.

John's mother used to be very _____ about what she wore，although her family was not that rich.

We _____ close friends since we got to know each other in 2006, and we always keep in touch.

If you       these mark, you will get a total of 90.

Now a lot of new technologies can ___________ problems in industry.