心脏杂音的论述，错误的是

A．杂音最响部位常与病变部位有关

B．二尖瓣关闭不全的杂音向左腋下传导

C．二尖瓣狭窄的隆隆样杂音局限于心尖区

D．心动周期不同时期的杂音反映不同的病变

E．主动脉瓣狭窄的杂音向胸骨下方传导

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