对修理费用高，零件更换困难，故障可以监测且监测费用不高的设备，应采用的修理方式是( )
A．事后修理
B．定期修理
C．预知维修
D．改善维修
参考答案：C
Half of the students done most of the work. The rest of the work rather difficult. [ ]
A. have ; is
B. has ; are
C. have ; are
D. has ; is
To gain a bigger _______ internationally, many companies are striving to make their products more competitive.
A．hold
B．share
C．interest
D．part
