To add refrigerant to the low side of an air conditioning system, the refrigerant should be introduced through the_______ .

A．suction service valve as a vapor

B．suction service valve as a liquid

C．discharge service valve as a vapor

D．charging valve as a liquid

[单选题]The temperature of the refrigerant in the evaporator coil depends mostly upon the ___.A．refrigerant pressure in the evaporatorB．cooling water temperature to the condenserC．heat load in the refrigerator compartmentD．solenoid valve in the liquid line

[单选题]The top of the Great Wall is ______for five horses to go side by side.A.wid

[单选题]The top of the Great Wall is ______for five horses to go side by side.A.wid

[单选题]France and several other European countries sent their medical teams to wor

[单选题]In the expression “On the other side of the coin” in Para. 3, “the coin” is used to refer to______。A． the misunderstanding of scienceB． the scientific explanationC． the money needed in scientific researchD． the curiosity of scientists and nonscientis

[单选题]If you don not side with me,__________.A．neither will theyB．so they won’t neitherC．neither they willD．so won’t they

[单选题]There are many trees on ______side of the river．A．bothB．eitherC．allD．a

[单选题]It is uncertain side effect the medicine will bring about, although about two thousand patients have taken it.A．thatB．whatC．howD．whether

[单选题]Which of the following is a common side effect of taking Lipitor?A． Face swelling.B． Upset stomach.C． Kidney failure..D． Muscle weakness.

[名词解释] 副反应（side reaction）