原肾型排泄器官主要由（）和（）组成，前者起源于（），后者则由_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题填空题

原肾型排泄器官主要由（）和（）组成，前者起源于（），后者则由（）和（）组成。其主要功能是（）。

答案

参考答案：排泄管；焰细胞；外胚层；管细胞；帽细胞；调节体内水分的渗透压

完形填空

Years ago,when I was working at a children’s institution,a boy　1　up in the waiting room.It was David.He had　2　his parents.He was very sad　3　to talk to others.
The first two times we met,David didn’t say a word.He sat in the chair and only　4　up at the children’s drawings on the wall.As he was about to leave 5　the second visit,I put my hand on his　6　.He didn’t shrink (退缩) back,but he didn’t look at me either.
“Come back next week,” I hesitated a bit.
He came,and I suggested we play a game of chess.He 7 .After that we played 8 every time,in complete 9 and without making any eye contact.It’s not 10 to cheat in chess,but I admit that I made sure David won 11 .
It seemed as if he enjoyed my 12 .But why did he never look at me？Perhaps he sensed that I respected his suffering.I kept wondering and 13with him,until some months later, 14 ,
he looked up at me.“It’s your turn,” he said.
After that day,David started 15 .He got friends in school.He wrote me a few 16 about how he would try to get into university.After some time,the letters 17 .Now he had really started to live his own life.
I learned how 18cures pain.And David showed me how one—without any 19 —can reach out to another person.All it takes is a shoulder to cry on,a 20 touch and an ear that listens.

A．now and then

B．more or less

C．once or twice

D．all the time

小题13:A．playing B．competing Carguing D．fighting

C．impatiently

B．compositions

填空题

凡接触病人伤口、血液、破损粘膜或进入人体无菌组织的各类口腔诊疗器械，包括牙科手机、车针、根管治疗器械、拔牙器械、手术治疗器械、牙周治疗器械、敷料等，使用前必须达到（）。