In the following question, out of the four alternatives, select the alternative which will improve the bracketed part of the sentence. In case no improvement is needed, select "no improvement".
(Upto) the time he wasn’t here, we were not sure if he will actually come.
In the following question, sentence given with blank is to be filled in with an appropriate word. Select the correct alternative out of the four and indicate it by selecting the appropriate option.
The enzyme was the _____________ that triggered the chemical reaction.