Is an experiment in which participants do not know if they are in the experimental or the control group, but the experimenters do know which participants are part of which group?

What did the first language sound like

Last week i was assigned a thematic. we have groups of three but the people i was assigned with haven't been in school for days. i would appreciate if anyone can me with my thematic . i highlighted most of the important steps and i circled my thematic topic. in desperate need : ( its due on february 19

Describe two recent or ongoing space missions.