钻具总长等于（）长度之和。
A、钻头、钻杆、钻铤及方钻杆
B、钻铤、钻杆、接头及钻头
C、钻杆、钻铤及钻头
D、接头、钻杆及钻铤
参考答案：B
_____ your father _____ a new computer? [ ]
A. Is, have
B. Do, have
C. Does, have
D. Does, has
秦始皇巩固专制主义中央集权制度的措施。
