吞吞吐吐 -------- hesitate in speech

例句：
A: Black hesitates in speech since he was young.
布莱克从小说话就吞吞吐吐。
B: It is a bad habit. You must help him to change.
这是个坏毛病，你必须帮他改过来。

同义词：
prunes and prism
hem and haw