tā / xīn lǐ / zhí / dǎ mèn léi / bù zhī dào / duì fāng / shuō / de / shì / zhēn / shì / jiǎ

他心里直打闷雷，不知道对方说的是真是假。

He kept wondering inwardly, not knowing whether what the other person said was true or false.