急性毒性试验中最常用的染毒途径（）
A.经口灌胃染毒
B.经呼吸道染毒
C.经皮肤染毒
D.经注射途径染毒
E.以上都不对
参考答案：A
Boys and girls , don't forget your report. It ____ today.[ ]
A. can't finish
B. can't be finished
C. should finish
D. should be finished
结合教育实际，论述儿童心理发展的动力。
