Choose the underlined words or phrases that are not correct in standard written English
31.He came to visit me , was bringing his brother with him
32.Mumps are a very common disease which usually affects children
33.He has less friends in his class now than he had last year
34.All writting was done with hand until the invention of the printing
35.Christoper Columbus has salied  from Eurpore in 1942 and discocovered a new land
36.You can do this math problem by yourselves .You're a student smart enogh to figure it out
37.Every night I open the bedroom window so that to let in some fresh air
38.Our company is sucessful enough to start several new branches in overseas
39.Do you enjoy being alone sometimes, or do you prefer being with other people all the time?
40.I'm palnning to get a car as soon as I can afford buying one