B .
C .
D .
>1

的菱形,且∠BAD=120°,且PA⊥平面ABCD,PA=
,M,N分别为PB,PD的中点.
余家贫,耕植不足以自给。幼稚盈室,瓶无储粟,生生所资,未见其术。亲故多劝余为长吏,脱然有怀,求之靡途。会有四方之事,诸侯以惠爱为德,家叔以余贫苦,遂见用于小邑。于时风波未静,心惮远役。彭泽去家百里,公田之利,足以为酒,故便求之。及少日,眷然有归欤之情。何则?质性自然,非矫厉所得;饥冻虽切,违已交病。尝从人事,皆口腹自役。于是怅然慷慨,深愧平生之志。犹望一稔,当敛裳宵逝。寻程氏妹丧于武昌,情在骏奔,自免去职。仲秋至冬,在官八十余日。因事顺心,命篇曰《归去来兮》。乙巳岁十一月也。
(《归去来兮辞·序》)
①脱然有怀,求之靡途②及少日,眷然有归欤之情③饥冻虽切,违己交病④于是怅然慷慨,深愧平生之志⑤于时风波未静,心惮远役⑥生生所资,未见其术
①家叔以余贫苦,遂见用于小邑。
②适莽苍者,三餐而反,腹犹果然。
踢足球是我国青少年喜爱的一项体育运动,如图所示是一次精彩的传球攻门过程,下列说法正确的是( ) 

,
满足
,
,不等式
恒成立,则
的最大值为( )
B .
C .
D .
“国风舞蹈”发轫于视频平台,早期的表演者大多并非专业舞者。随着这类短视频的影响力逐渐增强, ______。一些年轻的舞蹈演员纷纷开通个人账号,上传作品,成为创作国风舞蹈作品的有生力量。碧柳依依,翠裙飘飘;罗衣从风,衣袂翩翩。舞者用翩跹身姿演绎的汉风唐韵,像一幅幅瑰丽绚烂的织锦。这些作品艺术水准高、艺术感染力强,为观众带来良好审美体验。国风舞蹈与互联网关系密切。互联网不仅推动国风舞蹈传播, ______。与传统舞蹈不同,国风舞蹈创作者注重拍摄手法和短视频特效的应用,大量运用影视剧创作手法。国风舞蹈蓬勃发展,专业舞者与舞蹈爱好者相互学习,后者向前者学习专业技法和审美旨趣,前者汲取后者生动的表现手法和灵活的传播方式, ______,共同推动舞蹈艺术不断创新。
A
A farmer's cow was ill. he was worried and ask the vet to see it.
"What's the problem?"the vet asked.
"I don't know why my cow's lying down and won't stand up. She won't eat, and she's making a strange noise." the farmer said.
The vet looked at the cow."She's certainly ill and needs to take some very strong medicine." He took a bottle out of his box and put two pills into his hand."Give her these,"he said,"The pills should make her better."
"How should I give them to her?" the farmer asked.
The vet gave him a long tube (管子)."Put this tube in her mouth," he said, "then put the pills in the tube and blow. That'll make it." Then the vet went away.
The next day the vet came to the farm again. The farmer was sitting outside his house and looked more worried.
"How's your cow?" the vet asked.
"No change," the farmer said, "and I'm feeling very strange myself."
"Why?"
"I did what you said," The farmer answered. "I put the tube in the cow's mouth and then put two pills down it. But the cow blew first".

B .
C .
D .
is orange.
2C(g)+D(g)已达平衡状态的是( )