R and d program
[经] 研究与发展, 开发规划
🧩 词语组成解析
and
[ənd, ən,ænd]
conj. 和，与;而且;于是，然后;因此;
🗣️ 情景例句
Not to worry.
别担心。
Some people sometimes ask me what is the secret of such a tremendous growth.
有时有人问我取得如此惊人增长的秘密是什么。
Let us suppose that you are preparing a meal and keeping an eye on the baby at the same time.
假设你在做饭，同时又在照看孩子。