11. The public has complained that large quantities of waste water ______ into rivers without being cleaned, so large amounts of money ______ to solve the problem.

A．have poured; is needed

B．has poured; are needed

C．have been poured; is needed

D．have been poured; are needed

For many years, the principle goal of computer (73) was to write short pieces of code that would execute quickly. The (74) needed to be small, because memory was expensive, and it needed to be fast ,because processing power was also expensive.

A．users

B．programmers

C．computer

D．program