皮内注射法的目的是（）。
A.药物过敏试验
B.预防接种
C.局麻的先驱步骤
D.需迅速达到药效时采用
E.注射刺激性强的药物
参考答案：A, B, C
The new laboratories will be constructed this year, and local firms have been asked to ________ the
work. [ ]
A. assign
B. manufacture
C. provide
D. undertake
基线有哪些作用？
