题干

下列说法不正确的是

A:凡是铵盐都能与苛性钠共热产生NH3

B:NH4HCO3受热分解产生的气体经足量碱石灰干燥后可得到纯净的氨气

C:N2与O2在放电条件下化合属于氮的固定

D:工业硝酸略显黄色是由于里面含有Fe3的缘故

上一题 下一题 0.0难度 选择题 更新时间:2019-02-21 10:32:49

答案(点此获取答案解析)

D

同类题3

根据短文内容, 从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

    While serious training is important for all dogs, playtime is just as important.____ Use these games to help teach your dog how to play.

1)Hide and Seek

    Hide and seek isn't just for kids. Dogs can really enjoy this game. Pick up one of your dog's favorite toys or treats. Tell your dog to stay.____ When you are ready, call your dog to come to you. If possible, squeak(使吱吱叫)the toy or shake the treats. Reward your dog with praise and the toy/treat when she finds you.

2)Fetch

    Many dogs have a natural ability to fetch. Other dogs can be taught how.____Play indoors with a soft toy or outdoors in a fenced-in area with a ball or disc. For dogs that really  love to run, try this game of fetch!

3)Find the Treat

    Dogs have superior senses of smell, and most love to use their noses to find food. Let your dog use her brain and her nose to find hidden goodies. First, have your dog stay out of sight. Then, hide her favorite treats in various places around the room.____ If help is needed, you can lead her around or point to areas for her to explore.

    Whatever the game, safety comes first! Remember to watch your dog for signs of exhaustion or overheating when you are playing. Stop if your dog seems tired or shows signs of anxiety. ____When other dogs or people are around, it may create a dangerous distraction(分神).

A. Then, go to find a good hiding place.

B. Try different games to see which your dog responds to best.

C. A good game of fetch can be played almost anywhere.

D. You can include games in training as well.

E. Also be aware of your surroundings when playing with your dog.

F. Encourage your dog to play with other dogs.

G. Bring your dog back in and tell her to “go find!”

同类题5

阅读下面文章,完成小题。
                                                                                  对玉米的温软记忆
      不经意间,心底就会涌起丝丝柔情。为爱,还是为爱。这是一个亘古不变的主题。
  今夜,我谈情说爱,但不关乎爱情。我想唠叨的是对玉米的温软记忆。
  故乡的玉米天生丽质。金黄的色泽,光亮的质感,生动了乡间岁月。八、九月间,正是玉米的丰收季节,童年的我提着竹篮钻进了玉米地。一棵棵玉米风姿绰约,翠绿的衣衫在风中沙沙作响,红棕色的穗子轻舞飞扬,排排挺立如模特女郎。我则成了选美的裁判。我热衷的是杨贵妃式的美,谁最丰满,我就选谁。我喜悦地做着选、掰、装的动作,从来不觉得自己是个刽子手。
  经过我的精心挑选,竹篮里静卧了一篮睡美人。我高兴地提着它们回家,剥去翠绿的外衣,捋去细长的穗子,露出饱满的躯体。有时,那甜蜜的米粒里还会藏着可爱的小虫,在洞穴里探头探脑。这可是甜蜜的陷阱。见到它们,我往往用菜刀将那一块削去,然后用清水洗净,倒进装满水的铁锅里烘煮。不到一个小时,玉米的浓香就会弥漫整个房间,接下来,全家人开始享用。刚出锅的玉米烫手,小孩子都用干净的毛巾包住一头吃。不久,玉米的温度降了许多,拿在手里特温暖、柔软。太嫩的玉米水份多,甜甜的,软软的。牙齿没长好的小孩喜欢啃,牙齿快掉光的老人乐意吃。其实,那成熟的玉米才更有滋味,更有嚼头。
  少年的我在外地读书,很少归家,往往节假日才回来一趟。年年暑假回家,首先迎接我的便是笑嘻嘻的玉米。可是,我因长期在清淡的校园生活,肠胃已不习惯吸收这高营养的美食。第一天回去,刚吃了一个玉米就开始腹疼,我不敢再吃。父亲赶忙从医院拿来酵母片,吩咐我吃下。接连好多天,我都不敢尝一口那香喷喷的玉米。母亲眼睁睁地看见玉米被干光,而我却未能尝一口,心底里难受,就劝我再试试。说哪会那么巧,一吃就肚子疼呢。在母亲的一再劝说下,我便折了半个玉米吃。还没吃干净,肚子就疼起来,而且还疼得厉害。母亲焦急地说:“怎么这样灵验呢?就吃半个都不行。”“就是你一个劲让她吃,她说了不吃,你还叫她吃。这下可好。”父亲厉声呵斥着母亲,然后又急冲冲去医院拿酵母片。我目睹这种情景,两行温软的液体立刻从眼眶溢出。母亲见了连忙问:“怎么这么疼呢?”我流泪笑着说:“并不是很疼的。”其实我想说这是幸福的泪,可我说不出口。
  后来,我这娇气的肠胃逐渐适应了,不知不觉又能吃了,母亲的心才得到满足。
  如今,每次见到玉米,我都会想起它带给我的暖暖的、软软的感觉。