按要求填空:
①锌元素符号____.
②两个氢原子____.
③三个氧分子____.
④钠离子____.
⑤氧化钙中钙元素的化合价____.
一个数的16倍是43.2,这个数的30倍是____
右图瓶子中放入的是萌发的种子,种子底下是氢氧化钠溶液,中间用一个筛网将其隔开,a是红墨水珠,试推测玻璃管中的红墨水珠的移动方向是( )
选择合适的选项完成对话。
Cheng Jie: Good morning!
Amy: ____
Cheng Jie:Nice to meet you.
Cheng Jie: ____
Amy: My name is Amy.
Cheng Jie:____
Amy: I'm from the USA.
A. Where are you from ? B. Nice to meet you, too.
C. What's your name? D. Good morning.
根据汉语提示完成句子