dr
                    - 目前普通民用GPS和DR组合定位设备(GPS惯性设备)已经可以达到lOOOm无GPS信号的情况下的航向精度和()的距离精度。
 - Now Dr Li operates _______ 15 patients a day. [ ]
 - Dr. Ma used to __________in a hospital.
 - Dr. Bethune ________ working in spite of cutting his hand during an operation.
 - Did you see Dr Ma yesterday afternoon?— No. When I got to his office, he ______ already.
 - Did you see Dr Ma yesterday afternoon? —When I got to his office, he ______. So we just talked little.
 - You seem to have known Dr Smith for a long time.—- That’s true. ______ he joined our club six years ago.