Alike light waves, microwaves may be reflected and concentrated.

These discoveries may throw light on the origins of the universe. The underlined part mean

He devised an______to measure light waves.A．implementB．instrumentC．applianceD．equipment

The speed of radio waves is equal to ________of light. A. those B. that C. the one D. t

Which of the following is INCORRECT？A．The Internet can be connected by light waves.B．You c

In the writers opinion, what problem affects microwave ovens？A．Children may misuse them.B．

Why does Dr Povey say the fact that light waves can not penetrate walls is a bonus？A．Becau