450)=450">

181. What are you doing?
你正在干什么？

182. I'm reading a book.
我正在看书。

183. What's your friend doing?
你朋友正在干什么？

184. He's studying his lesson.
他正在上课。

185. I'm not doing anything right now.
我现在什么都没干。

186. Where are you going?
你要去哪儿？

187. I'm going home.
我正要回家。

188. What time are you coming back?
你什么时候回来？

189. I'm not sure what time I'm coming back.
我不确定我什么时候能回来。

190. What are you thinking about?
你在想什么？

191. I'm thinking about my lesson.
我在想我的功课。

192. Who are you writing to?
你正在写谁？

193. I'm writing to a friend of mine in South American.
我正在写我一个南美的朋友。

194. By the way, who are you waiting for?
顺便问一下，你在等谁？

195. I'm not waiting for anybody.
我没有在等任何人。