Tom, our manager, ________ for American in two days and he has asked me to find out when the earliest plane ________ next Sunday.
A:is leaving; takes off
B:will leave; is taking off
C:is to leave; is going to take off
D:leaves; will take off
藻类植物、苔藓植物和蕨类植物的共同特点是( )。
以下关于美国南北战争历史意义说法正确的是( )
①国家和民族的统一得到维护 ②废除了黑人奴隶制度
③宣告北美13个殖民地脱离英国独立 ④为美国资本主义发展扫清了障碍