击剑的（）练习贯穿于击剑训练的整个过程，运动员从初级阶段到高级阶段，从初学者到运动健

内分泌激素作用原理的第二信使学说的主要内容包括（）

A.cAMP激活蛋白激酶系统，引起靶细胞的反应

B.激素作为第一信使与细胞膜受体结合

C.细胞膜上腺苷酸环化酶系统激活

D.在Mg²⁺存在的条件下，胞质中的ATP转化为cAMP

E.含氮激素与类固醇激素作用原理相同

与红细胞分化成熟有关的维生素是（）

A.维生素B₁和叶酸

B.维生素B₁和遍多酸

C.维生素B₁₂和叶酸

D.维生素B₁₂和遍多酸

小明用右下图形式对所学化学知识进行归纳，其中甲包含了乙、丙、丁，下列关系中正确的是（　　）

A．干燥剂：苛性钠、浓硫酸、生石灰

B．人体必需的微量元素：碘元素、铁元素、氧元素

C．合成纤维：涤纶、腈纶、棉花

D．合金：焊锡、不锈钢、黄铜

To Whom It May Concern:

On March 5, 2012 , I bought a Perfect Muffin Kit from your store at Midfield Shopping Center. The cashier who assisted me was George. George was very friendly and told me that the Perfect Muffin Kit would live up to the guarantee on the box: “Perfect Muffins Every Time!”.

Unfortunately, this product did not live up to what it promised . The muffins I made were far from perfect . I followed the directions in the package very carefully . First , I removed the bag of mix from the box. Then , I poured it into a bowl. Next, I added the correct amount of water to the mix and stirred it. According to the directions, after stirring the mixture , I added half a cup of dried grapes, nuts , berries, or another favorite ingredient . My favorite ingredient happens to be hot sauce . I find that a bit of hot sauce makes pizza and soup taste very delicious. So, continuing to follow the directions, I added half a cup of hot sauce to the mix and stirred it. Finally, I poured the mix into muffin tins and baked it in the baker at 350 degrees for exactly 20 minutes.

When the muffins finished baking, I was very excited to eat the “Perfect Muffins” as promised on the box. You can imagine my disappointment when, upon tasting the muffins, I discovered that they were not perfect. These muffins were , in fact , absolutely terrible. Not even my dog was interested in eating these supposedly “perfect” muffins.

I would appreciate a full refund( money to be returned) of $3.99 for this product as soon as possible. Enclosed are the receipt, the empty box, and one of the un-perfect muffins so that you can experience it for yourself . Thank you for your attention to this matter.

Sincerely，

Michelle Bauer

小题1:This letter is most likely addressed to _______.

A．a local storeowner

B．the owner of the muffin mix company

C．the clerk at a local muffin bakery

D．George, the cashier who sold the muffin mix小题2: The tone(语气 ) of the author can best be described as ________.

A．embarrassed

B．hopeless

C．disappointed

D．disgusted小题3:The author was unhappy with the product because________.

A．the directions of the product contained a mistake

B．it was not up to the promise made on the box

C．it was too difficult to follow the directions

D．it was worth less money than she paid for it小题4:The author’s main purpose in writing this letter is to ________.

A．prevent others from making the same mistake

B．persuade the company to change the wording on their box

C．get back all the money paid from the shop

D．complain about how bad the muffins tasted

流行性乙型脑炎的流行病学正确的是（）

A.流行性乙型脑炎患者和隐性感染者是主要传染源

B.我国流行性乙型脑炎流行主要集中在秋季

C.流行性乙型脑炎集中暴发少，家庭中多人同时发病少见

D.三带喙库蚊是主要传播媒介及长期储存宿主

E.流行性乙型脑炎是人畜共患的自然疫源性疾病，主要分布在亚洲