现有500kg某药粉，要求制成3000粒重0.5kg的水丸，其起模用粉量为(kg)()

A．16.67

B．0.625

C．5

D．18.74

E．18.21

— I think ______ of the materials I listened to at the beginning of the exam ______ easy.

— I think so.

A．three fourths, is

B．third four, are

C．three fourths, are

D．three fourth, are