If Alexander Fleming hadn't discovered penicillin, millions of people would have died from bacterial infections., If humans hadn't invented the printing press, books would have remained much more expensive., If the asteroid hadn't hit Earth 66 million years ago, the dinosaurs wouldn't have become extinct at that time., If Marie Curie hadn't studied radioactivity, scientists would have made slower progress in understanding radioactive elements., Scientists wouldn't have discovered the structure of DNA in 1953 if they hadn't studied X-ray images., Police wouldn't have identified so many criminals if they hadn't started using fingerprints in the late 19th century.

بواسطة

لوحة الصدارة

النمط البصري

الخيارات

تبديل القالب

استعادة الحفظ التلقائي: ؟