光固化粘接剂中粘接性单体的含量是（）
A.0.3%～0.5%
B.0.1%～0.3%
C.0～5%
D.7%～8%
参考答案：C
计算机应用最广泛的领域是( )。
A) 过程控制和信息采集 B) 办公自动化和数据处理C) 计算机辅助设计和辅助制造 D) 科学与工程计算
—What happened to Mark yesterday?
— He arrived at the station too late, _____ , he missed the early train. [ ]
A. therefore
B. however
C. because
D. as
