How did scientists bring back she Spanish Flu?

By replacing the genes for either the 1918 virus’s surface protein

Explanation:

CDC researchers and their colleagues have reconstructed the influenza virus that caused the 1918-1919 flu pandemic.

answer

crater lake was formed when mount mazama produced a large eruption and collapsed to form a caldera, which then filled with water forming a lake.

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.