酵母菌在有氧时进行有氧呼吸，无氧时进行无氧呼吸，将酵母菌放在含有培养液的密闭的锥形瓶中，测得CO₂的释放量是O₂的吸收量的3倍，则有氧呼吸与无氧呼吸消耗葡萄糖的比为（   ）

用下列词语造句。

①一触即发：

②朝不保夕：

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）