根据句意，写出括号内所给单词的适当形式。
【小题1】It’s too early to draw a conclusion now. A _________ (far) discussion is still needed.
【小题2】The small rivers in my hometown are much more _______ (pollute) than 10 years ago.
【小题3】You can’t imagine how much difficulty I had _________ (achieve) the balance between my family and my work.
【小题4】The terrible accident _________ (effect) him a lot and changed his dream of life.