We can never expect ________ bluer sky unless we create________ less polluted world.
According to the job advertisement, ______will be given to the candidates with working experience.
Susan was expecting her favourite singers, but to her disappointment, ______ appeared.
It was ______ great shock to the girl when _____ word came that her close friend died in the severe earthquake of Haiti.
— Who would you rather _____ your graduation ceremony tomorrow, your parents or friends?— All of them.
In terms of the knowledge of science, few students in our class can really ______ Christopher.