历时lì shí
last a period of time, take a period of time
奥陶纪ào táo jì
Ordovician period
短期duǎn qī
short-term; short period
原声例句
stanger things
Where were you this morning? I missed first period.
你在这儿干嘛 -你觉得呢。
TED-Ed(视频版)
Excess steroid use can also reduce fertility in males and females— by reducing the sperm in semen or by causing missed periods and conditions like polycystic ovary syndrome.