Укажи какой предлог пропущен в каждом предложении, если его не нужно, поставь прочерк – 1) My friends flied __ a hot - air balloon last summer.
2) This hunter go ___ safari every year.
3) He has climbed ___ a mountain for 3 days.
4) Look at this beautiful river! Let’s camp ___ a riverbank!
5) I haven’t a passport and I can’t travel ___abroad.
6) This brave explorer walk ___ the rainforest.
7) Aren't you afraid to swim ___ dolphins?