计算:(-17)+23+(-53)+(+36)
(-17)+23+(-53)+(+36)
=(-17)+(-53)+23+(+36)
=-70+59
=-11.
关于我国自然资源基本国情的说法,正确的是
A.我国是世界上的资源大国,而且许多自然资源人均占有量居世界首位
B.我国许多自然资源数量大,但种类少
C.我国人均资源量相当于世界平均水平
D.自然资源总量丰富,人均资源占有量不足
Little Tom _____ finished his homework; otherwise, he wouldn't be listening to music.[ ]
A. can have
B. must have
C. should have
D. might have