@LonelyGamer,
...achievements of science.
...cannot but rejoice
The courageous, persistent, persevering person…
They also develop…
The (or A) Scientist creates…
…, and too bad.
Aesthetic pleasure, joy, all such feelings fill (accompany?) daily activity of the scientist
The scientists is pleased in his work because any negative reaction disappears soon after he has dived into research
So science helps mitigate such troubles...
All above grammatical, I hope. However I agree with Cis abvove that you might benefit by combining sentences in a logical fashion
Science has developed incredibly fast over the past two centuries, growing to fantastic proportions, its achievements having made our lives more comfortable. Especially we must remember the great achievements of medical science, quickly learning to cure many diseases and achieving other discoveries scientists cannot but rejoice