必须用中心静脉供给营养的。一般都选择连续使用超过
A．1周B．2周C．3周D．4周E．5周
参考答案：B
It is requested that each of the teachers invited a performance at the party.
A．should give
B．will give
C．has to give
D．must give
多层建筑是指3～7层的房屋，或高度在21m以下的建筑。
