A:国家政策
B:高温多雨的气候
C:便利的水陆交通
D:国际市场需求
用所给词的适当形式填空
(1)Autumn is a____(wonder)season.
(2)We all hope____(have)a long holiday.
(3)I____(buy)a new car the day before yesterday.
(4)I like doing some____(shop)with my parents.
(5)He did some____(read)last night.
始终沿水平方向匀速飞行的飞机,在投放救灾物资的过程中( )
已知m=1+2,n=1-2,且7m2-14m+a3n2-6n-7=8,则a的值等于( )