按照完成作业行为方式的不同，可以把作业分为()
A．口头作业
B．书面作业
C．观察作业
D．实践作业
参考答案：A, B, C, D
下列不常用的动物接种途径是（）
A.皮下注射
B.静脉注射
C.腹腔注射
D.肌内注射
E.足部注射
As you ____new words in context, it is a very good method for you to guess their meanings. [ ]
A. come about
B. come across
C. come out
D. come up
