1) B
2) A
3) B
4) A
Shí gè yìbǎi jiùshì yìqiān.
1） 十个一百就是一千。
Ten hundred add up to one thousand.
Jiàoyù duì háizi de chéngzhǎng lái shuō shífēn zhòngyào.
2） 教育对于孩子的成长来说十分重要。
Education is very important for the growth of children.
Tā jiāodài wǒ qiānwàn búyào wàngjì suǒ mén.
3） 他交代我千万不要忘记锁门。
He told me do not forget to lock the door.
Zhōngyú bù zhǐyǒu Zhōngguórén zài xuéxí hànyǔ le.
4） 终于不只有中国人在学习汉语了。
Finally, not just Chinese people are learning Chinese.
于 (Yú), preposition. Here are some useful phrases of “于 (Yú)”:
“对于 (Duìyú)”: for.
“关于 (Guānyú)”: about, in regard to, respect.
“于是 (Yúshì)”: then, as a result of.
“等于 (Děngyú)”: equal.
“终于 (Zhōngyú)”: finally, at last.
千 (Qiān), usually refers to “thousand” but it also has some other meanings.
Here are some useful phrases about “千 (Qiān)”:
“千万 (Qiānwàn)”: be sure to…, must.
“秋千 (Qiūqiān)”: swing.