10.The young lady coming over to us _____ our English teacher; the way she walks tells us that!

　must be

　can be

　would be

　could be

正确答案：A

解析：

解析:向我们走来的这位女士一定是我们的英语老师,她走路的样子告诉了我们这一点。
表示推测的可能性由弱到强为might(很不确定,最弱的猜测)<may<could<can<should<ought to<would<will<must(很有把握,最肯定的猜测)

50.Don't believe whatever he tells you.

49.It is known to all that exercises are good for health.

48.You needn’t go there anymore. He already knows about it.

47.I knocked on his door but nobody came to answer it.

46.Fred was such a hardworking student that he soon came out first in the class.

45.It has not been decided yet whether they will take part in our experiment.

44.This one's pretty, but it costs too much.

43.This is the worst hospital I have ever seen.

42.My classmate is much cleverer than I.

41.Fred was such a hardworking student that he soon came out first in the class.