(1) _____ballet dancers learn five basic position for the arms and feet. A. all of B. of every C. all D. every 我不明白all 和 all of 的用法 这道题为什么选 A ???
(2) A liquid that might be a poor conductor when pure is often used to make solutions that readily transmits electricity. 我觉得 pure 是adj. 不能作主语的 但是我知道transmits也错了 不明白?