彼らの筋肉は硬直している。

Meaning
their muscles are rigid

Vocab used in this sentence

彼ら
they, their, them
to, of
筋肉
muscle, muscular, sinew, brawn
a, the, is, am, are, will
硬直
rigor, strictness, hardness, severity, harshness, stiffness, rigidity, inflexibility, sternness, hardship
and, shi, four, death
the, it, have
いる
are, to be, to stay, to have, necessary, to exist

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