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1·Roses are beautiful flowers.

玫瑰是美丽的花朵。youdao

2·Rabbits are very cute.

兔子很可爱。youdao

3·Rainbows are very gorgeous.

彩虹非常绚丽。youdao

4·Rivers flow cheerfully.

河流流淌得很欢快。youdao

5·Rockets can fly into space.

火箭能飞向太空。youdao

6·Robots are very interesting.

机器人很有趣。youdao

7·Rings are very beautiful.

戒指很漂亮。youdao

8·Radios have clear sounds.

收音机声音很清晰。youdao

9·Running is good for health.

跑步有益健康。youdao

10·Raisins are delicious snacks.

葡萄干是美味的零食。youdao

(1)R and dabbr. 研究发展（Research and Development）

(1)R wave非线性波