1) The students of... our group are good .at.. english. They work hard .at.. their pronunciation and grammar.
2) When Kate fell .behind.. the group .in.. the history .of.. the english language, everybody was ready to help her .with.. this subject. It took her a week to catch .up.. .with.. the group. Now she is very strong .at.. this subject.
3) Peter makes many mistakes ..IN. his speech. That`s because he works .by.. fits and stsrts.
4) Yesterday we had a lecture .on.. history, a seminar .in.. philosophy and a class .of.. English.
5) At... the end .offor.. the first term we shall have three exams.
6) It`s high time to start reading ... .for.. your exams.
7) Don`t miss classes, otherwise you may fail .in.. English.
8) What subject are you weak (strong) .at..?