Do you have experience with online classes? I must admit at first I found online classes quite uncomfortable! Although I used 1. computer every day, I didn't get used to chatting for 2. long time. So when I took part in 3. group's scheduled weekly chats, I had 4. hard time keeping up. By 5. time I'd finished typing in my responses, I'd missed about 6. dozen comments. And by 7. time I'd answered 8. question, we were already on to 9. third topic. To solve the problem, I decided to write down the main points of the topics for 10. coming weekly chat and preview 11. lessons. This is where I began to see 12. real help of the online environment. I was able to log in any time of day or night to review 13. homework, to see other students' comments, or to add my own comments to 14. week's lecture. Most of the students in our study group were from other cities or even other countries. Their different views certainly made 15. class interesting! Overall, I found the class enjoyable and I felt I learned a lot.
都是填冠词的。
这个练习的答案给的是第9个是a,第10个是the。但我总觉得不确定。