1.  Fill in the gaps in the following sentences:         Electromagnetic waves that are used for satellite communications and mobile phones are         .          Microwaves can go through           and          .         Infrared is reflected by                    .         Infrared waves have              wavelength than microwaves.    2.  How Science Works         Choose the correct answer:         Scientists say that microwaves from mobile phones can warm the brain, this is based on ...         a prediction / a theory / data / a hypothesis.     3.  Higher tier only:         Explain how microwaves are used in cooking.    4.  What are the effects on human's health of infrared and microwaves?