光沿直线传播，这是众所周知的事。

It is known to all that light travels in straight lines.

youdao

光沿直线传播这是毋庸置疑的。

It is clear that light travels in straight lines.

youdao

稍加思索，就能理解光总是直线传播的。

With a little reflection, it may be seen that light always travels in straight lines.

youdao

稍加思索，就能理解光总是直线传播的。

With a little reflection, it may be seen that light always travels in straight lines.

youdao