《工程款支付证书》是由监理工程师签发给（）的。
A、建设单位；
B、承包单位；
C、监理机构；
D、造价咨询单位.
参考答案：A
The style of Western art has changed many times ______ Chinese art has changed less often.
A．while
B．before
C．since
D．however
He _____ his homework at school. [ ]
A. doesn’t do
B. don’t does
C. isn’t do
D. does not
