When I was on a study trip in Beijing,I made quite a few friends there.保持句意基本不变.______ ______study trip in Beijing,Imade quite a few friends there.
问题描述：
When I was on a study trip in Beijing,I made quite a few friends there.保持句意基本不变.
______ ______study trip in Beijing,Imade quite a few friends there.
答
because of
答
During a study trip,.