向一个栈顶指针为top的链栈中插入一个p所指向的结点时，其操作步骤为（）。
A. top->next=p;
B. p->next=top->next; top->next=p;
C. p->next=top; top=p;
D. p->next=top; top=top->next;
查看答案
球拍两面不论是否有覆盖物，必须无光泽，且是什么颜色？
A. 可以红色，可以黑色
B. 一面绿色，一面红色
C. 一面鲜红色，一面黑色
D. 两面是红色或者黑色
World Animal Day aims to raise the status of animals in order to improve their welfare around the world. It is _____ 4 every year.
A. Sep
B. Oct
C. Jul
D. Apr
Which of the following statements about the statistics of pet ownership in the US is wrong?
A. It's estimated that 78 million dogs & 85.8 million cats are owned in the United States. ～44% of all households in the United States have a dog, & 35% have a cat, according to American Pet Products Association (APPA).
B. APPA reports that 64% of dogs are purchased from breeders, while 23% of dogs & 31% of cats are obtained from an animal shelter or humane society.
C. ～6.5 million companion animals enter US animal shelters nationwide every year. Of those, ～3.3 million are dogs and 3.2 million are cats.
D. Each year, ～1.5 million shelter animals are euthanized (670,000 dogs & 860,000 cats). ～3.2 million shelter animals are adopted per year (1.6 million dogs & 1.6 million cats).
About ____ million research animals including mice, rats, and birds were killed in the US in 2016.
A. 20
B. 26
C. 30
D. 36
微信支付 
支付宝支付