要计算正确而有用的工程量，就必须掌握相应的工程量计算法则。
参考答案：对
Tommy was planning to buy a car the next week,______ he ______ enough for a used one．
A．by that time; had saved
B．by which time; had saved
C．by that time; saved
D．by which time; has saved
根据国家标准《厂矿企业内机动车辆驾驶员安全技术考核标准》规定，企业内机动车辆共分为（）大类。
A.八
B.九
C.十
D.七
