A：work
B：to work
C：walking
D：to walk
Please be careful of ____ (spell) these new words.
读句子选出正确答语。
(____) 1. Where is your home? A.Sounds good!
(____) 2. How do you get to school? B.It's on First Street.
(____) 3. See you. C.Sorry.
(____) 4. Let's play outside. D.I get to school on foot..
(____) 5. Don't cross the street. E.Bye.
当今世界正处在大发展大变革大调整时期，国际关系纷繁复杂，形势多变。但当今时代的主题未变，仍是（ ）
人体免疫缺陷病毒（HIV）入侵T细胞后，T细胞死亡。以下有关说法正确的是
