(A)
Germs(細(xì)菌)are everywhere.They are verysmall and you__1__see tllem.They are Hke theseeds of plants,but tlley are__2__.There couldbe hundreds 0f them 0n the point 0f a needle(針).We can not see tlle germs__3__but we cansee tllem with a mioroscope(顯微鏡)