单选题
[填句补文]Posture. A good posture makes you feel better about yourself. ________. This makes breathing more difficult， which in turn can make you feel nervous or uncomfortable.
A.If you are feeling down， you normally don‘t sit straight， with your shoulders inwards.
B.Body language is a broad term for several forms of communication using body movements or gestures.
C.Body language differs from culture to culture.
D.If you are at interviews， try to keep them still.
正确答案：A
答案解析：本段讲的是身体姿势。填充句后一个句子提到“this”会使呼吸更加困难，this显然指的是一种不太好的身体姿势，因此本题答案为A。