10.已知{an}\{a_{n}\}{an}是等差数列,a1+a2=1a_{1}+a_{2}=1a1+a2=1,a2+a3=3a_{2}+a_{3}=3a2+a3=3,则a3+a4=a_{3}+a_{4}=a3+a4=[ 5 ].