What fertility technique extracts ova, combines them with sperm, and after a few days, implants two or three blastocysts into the woman's uterus?

In vitro fertilization
       
Not much to say, the question pretty much defines the technique. The first successful birth via IVF happened with the birth of Louise Brown in 1978. There are some issues with IVF that can cause complications. Among them are multiple births (twins or triplets) due to multiple blastocysts successfully implanting in the woman's uterus.

The soviet union beat the us to the first successful launch, with the october 4, 1957, orbiting of sputnik 1, and later beat the us to have the first human in earth orbit, yuri gagarin, on april 12, 1961. the "race" peaked with the july 20, 1969, us landing of the first humans on the moon with apollo 11

From a high concentration to a low concentration.