When you________, use a handkerchief to cover your nose and mouth. This is particularly necessary in public places.

1. A.
   speak
2. B.
   whisper
3. C.
   sneeze
4. D.
   breathe

When you________, use a handkerchief to cover your nose and mouth. This is particularly necessary in public places.

       A．speak       B．whisper    C．sneeze      D．breathe

When you         , use a handkerchief to cover your nose and mouth. This is particularly necessary in public places.

A．speak              B．whisper          C．sneeze          D．breathe

When you________, use a handkerchief to cover your nose and mouth. This is particularly necessary in public places.