我国规定的植树节是每年的[ ]
A．4月12日
B．3月12日
C．4月份第一周
D．3月份第一周
B
Our flight to Guangzhou was ________by a bad fog and we had to stay much longer in the hotel than we had expected.
A．delayed
B．adjourned
C．cancelled
D．preserved
GPRS三种不同的MM状态是：（）状态、（）状态和（）状态。
