明朝时期广东地区的农业发展开始步入全国前列,经济作物方面,引进了()。
A.香蕉
B.龙眼
C.烟草
D.花生
参考答案:C, D
Bob and Jenny _____ know their teacher's name. [ ]
A. doesn't
B. does
C. don't
D. aren't
以下注射给药没有吸收过程的是()
A.血管内给药
B.皮下注射
C.肌内注射
D.腹腔注射
E.皮内注射