Insectpestsareamongtheleadingcausesofcropfailure.

Blue－green algae grow abundantly in salt marshes.

Themegaphone(microphone)makesthevoicesoundlouderbecauseitpointssoundwavesinonedirectionandkeepsthemfromspreadingoutinalldirections.

Food must be moist in order to have a taste.

Communicationisoneofthemostimportantbondsthatholdculturalsystemstogether.