【正文】 the adoption of an approach to space in which all parts of the canvas played an equally vital role in the total work。 and there are some of each type in the brain. These terms are used because nicotine mimics the action of acetylcholine at nicotinic receptors, whereas muscarine, an alkaloid from the mushroom Amanita muscaria, mimics the action of acetylcholine at the muscarinic receptors. Acetylcholine is the neurotransmitter produced by neurons referred to as cholinergic neurons. In the peripheral nervous system acetylcholine plays a role in skeletal muscle movement, as well as in the regulation of smooth muscle and cardiac muscle. In the central nervous system acetylcholine is believed to be involved in learning, memory, and mood. Acetylcholine is synthesized from choline and acetyl coenzyme A through the action of the enzyme choline acetyltransferase and bees packaged into membranebound vesicles . After the arrival of a nerve signal at the termination of an axon, the vesicles fuse with the cell membrane, causing the release of acetylcholine into the synaptic cleft . For the nerve signal to continue, acetylcholine must diffuse to another nearby neuron or muscle cell, where it will bind and activate a receptor protein. There are two main types of cholinergic receptors, nicotinic and muscarinic. Nicotinic receptors are located at synapses between two neurons and at synapses between neurons and skeletal muscle cells. Upon activation a nicotinic receptor acts as a channel for the movement of ions into and out of the neuron, directly resulting in depolarization of the neuron. Muscarinic receptors, located at the synapses of nerves with smooth or cardiac muscle, trigger a chain of chemical events referred to as signal transduction. For a cholinergic neuron to receive another impulse, acetylcholine must be released from the receptor to which it has bound. This will only happen if the concentration of acetylcholine in the synaptic cleft is very low. Low synaptic concentrations of acetylcholine can be maintained via a hydrolysis reaction catalyzed by the enzyme acetylcholinesterase. This enzyme hydrolyzes acetylcholine into acetic acid and choline. If acetylcholinesterase activity is inhibited, the synaptic concentration of acetylcholine will remain higher than normal. If this inhibition is irreversible, as in the case of exposure to many nerve gases and some pesticides, sweating, bronchial constriction, convulsions, paralysis, and possibly death can occur. Although irreversible inhibition is dangerous, beneficial effects may be derived from transient (reversible) inhibition. Drugs that inhibit acetylcholinesterase in a reversible manner have been shown to improve memory in some people with Alzheimer39。 im。j++) v+=a[i][j]。 } double Mean(double a[M][N] ,int m ,int n)，編寫函數(shù)定義，要求返回二維數(shù)組 a[m][n]中所有元素的平均值。 for(i=3。 i++) if(i%3==0 || i%5==0) printf(%d ,i)。 for(i=0。 int s=1。 程序?yàn)椋? int FF(int a[], int n) { int i,sum=0。 int p=1。 f=fnext。 } if(i*i=x)return 0。 } 假定 struct IntNode 的類型定義為： struct IntNode { int data。 3. include int SA(int a, int b) { if(ab) return 1。 i++) scanf(%s%d%f, a[i].name,amp。 for(i=O。 for(i=O。 a[i]=90) s+=a[i]。 x/=i。i5。 strcpy(,t)。 } 運(yùn)行結(jié)果： 11 13 20 25. include include struct Worker { char name[15]。 } 運(yùn)行結(jié)果： 20 42 24. include void main() { int a[3][3]={{3,5,7},{9,11,13},{6,8,20}}。 s1=s2=0。 } 運(yùn)行結(jié)果： 25 20 22. include const int M=20。y)。 } printf(%d %d\n， a， b)。 i++) if(strlen(a[i])len) len=strlen(a[i])。 i++) 8 if(a[i]%5) printf(%d ， a[i])。 } 運(yùn)行結(jié)果： 104 16. include void main() { int i， s=0。 float pay。 a[i]=a[M1i]。SB(a2)。 break。 break。 i++) { if(a[i]b1) b1=a[i]。i++) { if(s30) break。in。 for(i=0。 int i, i1=0, i2=0。 printf(%d ,f1)。 case 7: printf(%d ,2*x)。i++) s+=a[i]。 } 運(yùn)行結(jié)果： s=235 4. include int WF(int x, int y) { x=x+y。 } } 運(yùn)行結(jié)果： 2 5 3. include void main() { int a[8]={70,63,54,95,40,75,90,66}。 j5。 A* c。 59. 假定二維數(shù)組的定義為“ int a[3][5]?！闭Z句后得到的輸出結(jié)果為 _C_?！保瑒t每個數(shù)組元素的行下標(biāo)取值范圍在 _0~M1 之間。printf(%d,x/y)。 38. NULL 是一個符號常量，通常作為空指針值，它對應(yīng)的值為 0 。 4 32．若 x=5， y=10，則 xy的值為 0（假） 。 char* b?！?，則該數(shù)組所含元素的個數(shù)為 M*N 。2)。 printf(%d， x/y)。 char *func(int n)，則該函數(shù)的返回類型為 (D)。 3 (x0||y==5)的相反表達(dá)式為 (B)。 D. char a[10]=39。 A. (n+1)/2 B. n/2+1 C. n/21 D. n1 35. 在下列的字符數(shù)組定義中，存在語法錯誤的是（ D）。 A. cpp B. exe C. obj D. c 32. 設(shè)有兩條語句為 “ int a=12。 A. AA(int a， int b) B. AA(int， int) C. AA(int a。 2 A．讀取 B．寫入 C．關(guān)閉 D．打開 21. C 語言源程序文件的缺省擴(kuò)展名為 (D)。 A． 1 B． 2 C． 4 D． 8 18．假定有定義為“ int m=7, *p。 A． n1 B． n C． n+1 D． n/2 15．假定一個二維數(shù)組的定義語句為“ int a[3][4]={{3,4},{2,8,6}}。 A． x=0 || x10 B． x=0 amp。 D. char *p。 A. strlen() B. strcpy() C. strcat() D. strcmp() 7. 若用數(shù)組名作為函數(shù)調(diào)用的實(shí)參，傳遞給形參的是（ A）。 A. main B. MAIN C. name D. function 2．每個 C 語言程序文件的編譯錯誤分為（ B）類。 do i++。s。 A．空格或逗號 B．逗號或回車 C．逗號或分號 D．空格或回車 12．邏輯表達(dá)式 (x0 amp。 A． for B． while C． dowhile D． switch 14．假定 i 的初值為 0，則在循環(huán)語句“ while(in) {s+=i*i。 C． int Function(a)?！?，要