答案:2
解析:解析:本题考查的知识点为二次积分的计算.由相应的二重积分的几何意义可知,所给二次积分的值等于长为1,宽为2的矩形的面积值,故为2.或由二次积分计算可知
答案:2
解析:解析:本题考查的知识点为二次积分的计算.由相应的二重积分的几何意义可知,所给二次积分的值等于长为1,宽为2的矩形的面积值,故为2.或由二次积分计算可知
A. 各地区均衡发展
B. 各地区非均衡发展
C. 由西向东梯次推进
D. 由东向西梯次推进
A.
B. 0
C.
D. 1
解析:解析:
A. sat
B. seated
C. seat
D. sitted
A. off
B. over
C. through
D. past
解析:解析:put out my head(伸出头)解析:go out(下车)解析:go over (复习)解析:go through (碾过去)解析:past (经过)
A. taking
B. being taken
C. to have taken
D. have been taken
解析:解析:remeber doing 记得过去做的事情
A. us
B. we
C. our
D. ours
A. taking part in
B. took part in
C. to take part in
D. take part in