No one can sing ____ than Mary in her class.

We are _______ by doctors to eat more natural food and take plenty of physical exercises . [ ]

The kid is only three, but he can say________English words.

Professor Hawking stepped into the office he knew that there was no hope

Penicillin became the greatest drug of the 20th century, without ______ many people ______ from sickness or even small wounds.