21.完形填空。
阅读下面短文,从每题所给的A、B、C和D四个选项中选出可以填入空白处的最佳选项。
Every year, thousands of young inventors show their ideas at NICEE. Some kids get invited to NICEE. The main goal of NICEE is to help kids know real problems and find ways to 1 them.
To support this 2 , many schools now have invention clubs. Kids in the clubs work together. They look 3 ways to make life better. They might invent something to make a job 4 or make people safer.
For example, Lucca wanted to help people 5 his grandmother. She had to wear a breathing mask(面罩) in the hospital. That made it hard for others to hear her 6 . So Lucca invented a new mask. It has a microphone. It 7 the person's voice to a speaker(扬声器). Now users can talk with others.
Inventions can be simple. One winner, Maddox, made a new garden shovel (铁铲). The shovel has marks on 8 to help gardeners know how deep to dig their holes.
9 kids choose an idea, they have to build a model that works. They cannot spend more than $50. The invention must be something new. It also must fit inside a certain space.
NICEE shows the best inventions from the states. Young inventors get to meet one another. They see others’ great ideas. Some of them win prizes. They can 10 learn about ways to sell their inventions.
1. A. answer B. solve C. develop D. create
2. A. way B. chance C. goal D. decision
3. A. for B. into C. up D. at
4. A. harder B. easier C. worse D. stronger
5. A. as B. with C. by D. like
6. A. sound B. noise C. voice D. sign
7. A. hears B. says C. discovers D. sends
8. A. it B. him C. its D. them
9. A. Before B. Although C. When D. While
10. A. instead B. never C. finally D. even