已知点(m,n)在直线5x+2y-20=0上,其中m,n>0,则lgm+lgn(

题型:选择题

问题:

已知点(m,n)在直线5x+2y-20=0上,其中m,n>0,则lgm+lgn(  )

A.有最大值为2

B.有最小值为2

C.有最大值为1

D.有最小值为1

考点:基本不等式及其应用
题型:选择题

为了保持生活环境中的空气的新鲜和清洁,下列哪项做法不可取( )

A.绿化环境

B.保持室内空气流通

C.室内多放些绿色植物

D.保持环境卫生和个人卫生

题型:选择题

阅读理解。

  I am a middle school student. My name is Wei Fang. I am a girl. I'm thirteen

now. I study at Yuying Middle Scholl. I am in class 3, Grade 1. There are twenty

boys and twenty-three girls in my class.

  We have four lessons in the morning and two in the afternoon. We like

English very much. On weekends, I often go to movies with my friends. I like

action movies and comedies very much. I think they are exciting and interesting.

But I don't like documentaries because they are too boring. I often play soccer

ball for half an hour after school in the afternoon.

1. Wei Fang is _____.

A. a teacher

B. a boy

C. 13 years old

D. in Class 1, Grade 3

2. Wei Fang has _____ lessons on Monday.

A. 4

B. 2

C. 6

D. no

3. On weekends, Wei Fang often _____.

A. studies at school

B. goes to movies

C. plays soccer

D. does her

4. Her favorite movies are _____.

A. documentaries

B. action movies

C. comedies

D. both B and C

5. After school in the afternoon, Wei Fang often _____.

A. goes to movies

B. sings and dances

C. plays the guitar

D. plays football

题型:选择题

使用青霉素G无效的病菌为()

A.革兰阳性球菌

B.革兰阳性杆菌

C.革兰阴性球菌

D.铜绿假单胞菌

E.梅毒螺旋体

题型:选择题

新生儿易出现溢乳的原因,不包括以下哪项()

A.胃底发育差

B.下食道括约肌压力低

C.幽门括约肌较发达

D.胃扭转

E.胃呈水平位

题型:选择题

餐饮服务业的记录、票据的保存期限不得少于()年。

A.1

B.2

C.3

D.4

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