___with a difficult situation, John decided to ask his boss for advice.  [ ]

A. To face      

B. Having faced    

C. Faced      

D. Facing

园林工人经常修剪路旁的绿篱，目的是

A．抑制侧芽生长

B．解除顶端优势

C．抑制向光生长

D．抑制生长速度