镧系元素标记抗原或抗体作为示踪物的优点是 ()
A.镧系元素发光稳定
B.荧光寿命长
C.stokes位移大
D.激发光谱带较宽
E.荧光强度高
参考答案:B, C, E
判断项目盈利能力的参数不包括()。
A.项目资本金净利润率
B.偿债备付率
C.总投资收益率
D.财务内部收益率
–Would you like a cup of coffe?
--Sorry. I’ll have a cold drink rather than coffee.
A.would than
B.would rather
C.instead
D.instead of