下列事实能说明铝的金属活动性比铁或铜强的是（  ）

用括号内所给词的适当形式填空
⑴I enjoy reading this kind of ____  magazine. （每周）
⑵It is good for your health to ____  deeply. （呼吸）
⑶It ____  on the two sides of the river.（位于）
⑷A large number of new ____ will live in Yangzhou.（移居者）
⑸The small town is becoming more and more ____  and polluted.（拥挤的）
⑹His mother has devoted____ to the teaching of Home Economics.（she）
⑺The making paper was a Chinese____ . （invent）
⑻It is well ____  that Yangzhou is one of the most beautiful cities in our country.（know）
⑼He had been deeply affected by the____  death of his father. （suddenly）
⑽There will be ____  no rain tomorrow.（probable）

有些物理量不能直接测量，实验中我们是想办法通过测量与它大小相等的量（称“等效替代”）来完成的。下列几个例子中不是应用这种方法的是（   ）

有关细胞结构和功能的叙述，正确的是