重庆理工大学现任团委书记是（）
A.黄介彬
B.李国
C.谢春林
参考答案：A
She is a strong-willed woman and not once _______ in to any difficulty in her life.
A．she has given
B．did she give
C．she gave
D．has she given
化学毒剂按杀伤作用持续时间可分为哪两种？
