Security forces blocked journalists from attending the ceremony at the site, though vehicles transporting families could be seen heading there.
Other victims' family members have also appeared at congressional hearings, and numerous lawsuits have been filed against Boeing.
The crash came after another Boeing 737 MAX of Indonesian company Lion Air crashed in October, killing 189 people on board.
"Let me be clear: Ethiopian Airlines believes in Boeing. They have been a partner of ours for many years," Tewolde GebreMariam wrote in a statement.
An Ethiopian delegation led by Accident Investigation Bureau has flown the Flight Data Recorder and Cockpit Voice Recorder to Paris, France for investigation...
There were no survivors among the 149 passengers and eight crew on board a Nairobi-bound Boeing 737 that crashed shortly after takeoff from Addis Ababa....
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