某植物有花，叶脉一般具有网状脉，则可推断这棵植物可能是[ ] A．单子叶植物 B

56岁病人，绝经5年，近3月 * * 不规则流血；妇科检查：宫颈光滑，子宫如孕40天大，质软，无压痛，探宫腔7cm；分段诊刮：颈管未刮出组织，内膜质脆。入院后应首选的治疗原则是（）.

A.放射治疗

B.孕酮类药物治疗

C.化学治疗

D.免疫治疗

E.手术治疗

大枣在十枣汤中的作用是

A．治疗次要症状

B．协助君药加强治疗作用

C．制约君药的毒、烈性

D．起反佐作用

Louis Armp had two famous nicknames. Some people called him Bagamo. They said his mouth looked like a large bag. Musicians often called him Pops, as a sign of respect for his influence on the world of music.
Born in 1901 in New Orleans, he grew up poor, but lived among great musicians. Jazz had been invented in the city a few years before his birth. Armp often said, "Jazz and I grew up together. "
Armp showed a great talent for music when he was taught to play the comet at a boy’s home. In his late teens, Armp began to live the life of a musician, lie played in parades, clubs, and on the steamboats that traveled on the Mississippi River. At that time, New Orleans was famous for the new music of jazz and was home to many great musicians. Armp learned from the older musicians and soon became respected as their equal.
In 1922 he went to Chicago. There, the tale of Louis Armp began. From then until the end of his life, Armp was celebrated and loved wherever he went. Armp had no equal when it came to playing the American popular song.
His cornet playing had a deep humanity and warmth that caused many listeners to say, "Listening to Pops just makes you feel good all over. " He was the father of the jazz style and also one of the best known and most admired people in the world. His death, on July 6th 1971,was headline news around the world.

Which statement about Armp is true

A．His tale began in New Orleans.
B．He had been born before jazz was invented.
C．His music was popular with his listeners.
D．He learned popular music at a boy’s home.

如右图所示，有一定初速度的物体受到一个沿斜面向上的恒定拉力F作用，沿倾角为30°的粗糙斜面向上做直线运动，加速度大小为，在物体向上运动的过程中，下列说法正确的是(　　)

A．物体的机械能一定增加

B．物体的机械能一定减小

C．物体的机械能可能不变

D．物体的机械能可能增加也可能减小

一般情况下，生化反应池中接种污泥浓度达到（）g/L即可。

A.1

B.2

C.3

D.4