形状不规则物体的测密度

​ ( )4.They each _____ a CD in their bags.A.have B.has C.is D.are they each ____a CD in their bags.A have B has C is D are.为什么? 凯氏定氮法中加样后小漏斗的水封的作用是什么? they each ____a CD in their bags.A have B has C is D are Each student should __a notebook ,but they should not __ their bags.用bring 和carry填空,怎么选?有什么区别,都有拿着,带着的意思啊? 一种飞机最多可飞行6小时,飞出时顺风每小时飞1200米千米,返回时每小时飞960千米.这架飞机最多可飞出多少千米就应往回飞? 飞机一秒飞几米啊.一小时878公里 3.Tom flied to Japan with his family yester day.改为否定句5.Tom flied to （Japan） with his family yester day.对括号内的句子进行提问6.Tom flied to Japan with（ his family） yester day.对括号内的句子进行提问 中国自己制造的第一架战斗机是什么时候造的 明矾和焦亚硫酸钠反映吗?如题,明矾和焦亚硫酸钠是不是会发生反映? 除氧器水封筒的作用是什么? 两相按钮开关怎么接?图 220V 没有交流接触器 按钮后有8个接线点 It's in March. 舰载战机从航空母舰上起飞以__-为参照物,飞行员是静止的,以___为参照物,飞行员是运动的 with the bag in their possession是独立主格结构吗? In the struggle,the strap broke and,with the bag in their possession.with在这句话里翻译为什么?还有and后为什么要加逗号? 请问The strap broke and with the bag in their possession.句中的with表示什么意思可是and不是也表示‘和’意思吗 with the bag in their possession 不是be in one s possession 吗为什么这个句子不加be with the bag in their possesion这是什么句型?有什么语法? Tom together his best friend Nick are going to see a flim tonight.改错 钙在血液中以什么方式的形式存在 血浆蛋白在血浆中是以何种离子形式存在的?为什么? what's the price of the shoes?的回答是It's 还是 they're? 为什么what color ______Li Hua's shoes?it's black 的答语it's不是they're?呢 血浆钙的存在形式 What is the price of the gray shoes?的同义句 ship in volume in a ship还是 in ship或者in the ship 疑问句中选择 我国在探索月球方面的重大科学活动是什么 人类探索过月球的哪些地方 几年来,我国科学家们不断地对月球进行探索,你对此有哪些了解? 下图为人体的某种特异性免疫图解,⑤表示不同免疫细胞,Ⅵ表示生理过程,下列说法正确的是A、图示中①⑤细胞均能识别抗原B、细胞⑤产生的物质代表的是抗体或淋巴因子C、抗原经过过程Ⅰ