1.How often do you exercise? 你(你们)多久锻炼一次身体?
How often + 助动词do(does或did) + 主语 + do sth.? 疑问词how often是问频率(多久一次),(在这里助动词do(does或did) 是起帮助构成疑问的作用)与一般现在时或一般过去时连用，回答一般是用表示频率的副词，如：once, twice, three times…, sometimes, often, quite, often, never, every day, once a week , twice a month , three times a month , three or four times a month等。
How often do you go to the factory? Twice a week.你们多久到工厂去一次? 每星期两次。
“How often does he go shopping?” “He goes shopping once a month.”
2“What do you usually do on weekends?” “ I usually play soccer.”
“周末你通常做什么?”“我通常踢足球。”
第一个do为助动词, 在这起帮助构成疑问的作用;而第二个do则是实义动词。
翻译：What do you usually do on weekends? I often go to the movies.
What does she usually do on weekends? She sometimes go hiking.
3. “What’s your favorite program?” “It’s Animal World.”
“你最喜欢什么节目?”“动物世界。”
4. As for homework , most students do homework every day .
as for...意思是“至于;关于”，常用于句首作状语，其后跟名词、代词或动词的-ing形式(即动名词)。如：
As for him，I never want to see him here. 至于他，我永远不希望在这里见到。
As for the story，you\'d better not believe it. 关于那故事，你最好不要相信。
至于我自己，我现在不想去。As for myself, I don’t want to go now.
至于那个人，我什么都不知道。As for the man, I know nothing about him.
5. Mom wants me to get up at 6:00 and play ping-pong with her .
want to do sth. 意思是“想要做某事”;
want sb. to do sth.意思是“想要某人做某事”。如：
Do you want to go to the movies with me?你想和我一起去看电影吗?
The teacher doesn\'t want us to eat hamburgers.老师不想让我们吃汉堡包。