There are many different signs in the public. They tell you what to do or what not to do in

a place. Do you know what they exact mean? For example, if you go to see a film, you should

enter the cinema at the ENTRANCE and leave for the EXIT. You will either find NO

SMOKING signs in many cinemas. If you visit a museum, don’t take some photos inside the

halls. You are not allowed. You will find NO PHOTOS signs in many museum. When

you drive a car, don’t park in a street without a NO PARKING sign. Making sure

you understood the signs and you won’t get into any trouble.

手工充装液化石油气（）产生充装误差。

A.容易

B.不易

C.而人而异