关于tRNA叙述正确的是

A．分子上的核苷酸序列全部是三联体密码
B．可贮存遗传信息
C．是核糖组成的一部分
D．由稀有碱基构成发夹结构
E．二级结构为三叶草形

In your project，you can use all the following tools and techniques for risk response planning EXCEPT______．

A．strategies for negative risks or threats

B．contingent response planning

C．strategy for threat and opportunities

D．strategy for residual risks