改进包装方法十分必要。
还能这样说：
Improving the packaging is necessary.
It is necessary to make the packing better.
应用解析：
improve abilities 提高能力;
improve one's time 善用时间;
improve in health 改善健康
6. We have a big demand for this product.
关于这类产品我们有很大的需求量。
还能这样说：
We need to a big deal of this product.
There is a great demand for this product.
应用解析：
have many demands on one's time 时间不够支配;
in great demand 需要量很大
7. Our toys are lacked variety.
我们的玩具太单一。
还能这样说：
Our toys are too simple.
We don't have various toys.
应用解析：
a variety of 各种各样的，种类繁多的;
every variety of form 各种形式
8. Manufactures are interested in technical improvements.
生产厂商对技术改进很感兴趣。
还能这样说：
Manufactures are fond of the technical improvements.
Manufactures take a great interest in improving the technology.
应用解析：
bear interest 产生利息;提供利息;
give back with interest 连利息一起偿还某人;加倍还击某人