Answer:
complement
Step-by-step explanation:
The above answer is the correct answer.
Crew members must complement each other. This is true because from the excerpt, we were told that "An alternative to the shower is a wobbly platform that two or three crew members have to stand on and jointly balance with hand controllers". This depicts that these crew members must complement each other if they must use the platform. Without such synergy in balancing the platform, they will not be able to use it.