tú huà
shàng kè
shū yè
bǎi fàng
qiǎng xiān
jiāo gěi
____
She didn't know__________she could express her ideas clearly when she was invited to speak at the meeting.
整亿的数改写成用“亿”作单位的数,只需去掉末尾的( )个0,再添写一个“亿”字。
图为非洲略图,读图完成下题.