Помогите пожалуйста, здесь нужно поставить глагол в правильную форму
a) Usually we _______________ (to have) classes on the campus, but today we ________________ (to go) to the training airfield.
b) I ________________ (not to come) to the lecture yesterday. I ________________ (not to feel) very well. I hope my friends ________________ (to give) me the notes later.
c) Specialists from our Research Institute _______________ (just to finish) the experiment. They ________________ (to work) on it for a month.
d) My telephone _______________ (to ring) while I ______________ (to play) basketball in the sports center. It _______________ (to be) my friend Julie who told me I _______________ (to get) an excellent mark for my presentation.
e) I want to go to this concert tomorrow. I think that I _______________ (to finish) writing my course paper.
f) Samara University _______________ (to cooperate) with Oxford Polytechnic for 10 years by the end of this semester.
g) I _______________ (not to read) the book on history of aviation yet, so I _______________ (do) it all day tomorrow.
h) – What is that noise? What _______________ (to happen)?
- I ________________ (not to know). Maybe the machine _______________ (to break down).
j) Do you know who _______________ (to invent) this kind of engine?
k) I _______________ (to buy) this book last week, but I _______________ (to read) it yet.
l) Annie asked me how to use this machine. She _______________ (never to use) it before, so she _______________ (to know) what to do.

a) Usually we have classes on the campus, but today we are going to the training airfield. b) I didn't come to the lecture yesterday. I didn't feel very well. I hope my friends will give me the notes later. c) Specialists from our Research Institute have just finished the experiment. They have been working on it for a month. d) My telephone rang while I was playing basketball in the sports center. It was my friend Julie who told me I got an excellent mark for my presentation. e) I want to go to this concert tomorrow. I think that I will finish writing my course paper. f) Samara University will have cooperated with Oxford Polytechnic for 10 years by the end of this semester. g) I haven't read the book on history of aviation yet, so I will do it all day tomorrow. h) – What is that noise? What is happening? - I don't know. Maybe the machine broke down. j) Do you know who invented this kind of engine? k) I bought this book last week, but I haven't read it yet. l) Annie asked me how to use this machine. She has never used it before, so she didn't know what to do.