加工一批零件，甲单独做要 10 天完成，乙单独做要 8 天完成。现在甲、乙两人合作，多少天能完成这些零件的一半？
2018年12月，张阿姨把4000元的存入银行，定期三年，年利率是2.75%到期后，应得利息______元.
They flew a kite yesterday. (改为一般疑问句)
______ they ______ a kite yesterday?
It’s time for having dinner. (改为同义句)
It’s time ______ ______ dinner.
I can see some boats on the river. (改为否定句)
I ______ see ______ boats on the river.
Rubbish makes the streets messy and dirty. (对划线部分提问)
______ ______ the streets messy and dirty?
Yang Ling has a cough. (对划线部分提问) ______ ______ with Yang Ling?
There ______ (be) any students in the library yesterday.
The ______ (mouse) are going to eat some cakes.
David would like some ______ (potato) for lunch.
They are good ______ (friend). They’re in the same class.
