()不易识别且难以清除,其引起的产品质量差异是随机的,但一般影响并不大,不会造成废品。
A.交替性因素
B.偶然性因素
C.系统性因素
D.惯性因素
参考答案:B
______ himself with too much homework, he had no time to participate in outdoor activities.
A.Being occupied
B.Occupied
C.Occupying
D.To be occupied
用于立杆、纵向水平杆和剪刀撑的钢管长度以()为宜。
A.2.2
B.2.2~4.5
C.3.5~7
D.4~6.5