《畜禽肉水分限量标准》（GB18394-2001）规定，猪肉、牛肉水分限量为（）。A

On keeping a Diary in English

Keeping a diary in English is one of the小题1:__ (effect) ways to improve our English writing ability.

小题2:__ (compare) with other forms of writing, it is shorter and takes小题3:___ time. It can help us to develop the habit of thinking in English.小题4:___ we persist in this practice, gradually we’ll learn how to express ourselves in English. In keeping a diary in English, we certainly run up against many 小题5:__（difficult）. In the first place, 小题6:__ often happens that we have trouble 小题7:__(find) appropriate words and phrases to give expression to our mind. Secondly, there are many idiomatic ways of saying things in Chinese. And it is extremely hard for us to put them into English properly.

As far as I 小题8:_ (concern), my suggestion is that we should always have a notebook and a Chinese-English dictionary within easy reach. Whenever something beats us, we can first put it down in our notebook and then consult our dictionary. We can also turn to our English teacher for help, if necessary. In short, I believe that it is 小题9:__ great use to keep a diary in English for 小题10:__ development of our writing skills.

用化学用语填空：

(1)两个氢分子_________

(2)一个亚铁离子___________

(3)人体中含量最多的元素___________

(4)厨房中能调味和防腐的一种盐_________

“稚阴稚阳学说”首见于（）

A.《颅囟经》

B.《幼科发挥》

C.《幼幼集成》

D.《小儿药证直诀》

E.《温病条辨》

可降解聚合物P的合成路线如下：

已知：

(R为烃基)

(1)A的含氧官能团名称是________。

(2)羧酸a的电离方程式是_______________________________________________。

(3)B→C的化学方程式是_________________________________________________。

(4)化合物D苯环上的一氯代物有2种，D的结构简式是_______________________。

(5)E→F中反应①和②的反应类型分别是________。

(6)F的结构简式是_____________________________________________________。

(7)聚合物P的结构简式是_______________________________________________。

钻井液固相含量对钻井速度和钻头消耗量都有严重影响，因此，应控制固相含量，一般采用固相含量低于（）%的低固相钻井液。