B737NG22CH0028飞机上有几个独立工作A/P作动筒()
A.2
B.3
C.4
D.5
参考答案:C
可见光固化复合树脂最常用的引发体系是 ()
A.樟脑醌敏感波长400~500nm
B.樟脑醌敏感波长300~400nm
C.过氧化苯甲酰敏感波长400~500nm
D.过氧化苯甲酰敏感波长300~400nm
E.三丁基硼敏感波长400~500nm
He ______ very busy this week, he ______ free next week.[ ]
A. will be; is
B. is; is
C. will be; will be
D. is; will be