My best friend is studying abroad. It is impossible for us to meet each other now.
→ My best friend is studying abroad, so it is impossible for us to meet each other now.

They are going to build a new bridge across this river. Traveling will be much more convenient   
→ They are going to build a new bridge across this river, and traveling will be much more convenient.

It has been ages since our last encounter. I still remember him clearly.
→ It has been ages since our last encounter, but I still remember him clearly.

I went down with flu last week. I had to postpone my work.
→ I went down with flu last week, so I had to postpone my work.

I think the festival will be full of fun. Many people will enjoy it.
→ I think the festival will be full of fun, and many people will enjoy it.

Students can choose to carry out a project on environmental issues. They can conduct research on the topic of renewable energy.   
→ Students can choose to carry out a project on environmental issues or conduct research on the topic
of renewable energy.

My mother started a business trip last week. She hasn't returned home yet.   
→ My mother started a business trip last week, but she hasn't returned home yet.

My brother has grown up into an adult. He still enjoys playing with Lego.
→ My brother has grown up into an adult, but he still enjoys playing with Lego.