Between the twelfth and sixteenth gestational weeks, the amniotic cavity has enlarged enough to ——.

A —— pregnancy is an ectopic pregnancy coexisting with an intrauterine pregnancy.

decidua is the ——.

When scanning the fetus, the first thing to do is

In a pregnancy with high beta-subunit HCG, low alpha fetoprotein, what is this sonography risk assessment technique?

From 5 to 10 weeks GA the yolk sac progressively increases to a maximum diameter of 5 to 6 mm. By the end of the first trimester, the yolk sac —– appreciated sonographically.

The 20th of March 2026 represents the:

Why does Earth experience seasons?

During which Earth-Sun position (or positions) does the Equator (0 degrees latitude) receive the most direct insolation from the Sun (also known as the most direct Sun’s rays, overhead Sun, and subsolar point)?

If it is 3:00 pm, Monday in London (0 degree central meridian), then what time and day is it in Shanghai (120 degrees E central meridian)?