6) If _______ in the fridge, the fruit can remain fresh for more than a week.

6) If _______ in the fridge, the fruit can remain fresh for more than a week.
A) keepingB) be kept C) keptD) to keep
7) _______, we went swimming in the river.
A) The day being very hotB) It was a very hot day
C) The day was very hot D) Being a very hot day
8) I stayed up all night ________ to find a new solution to the problem.
A) tryingB) have triedC) try D) tried
9) ________ with the developed countries, some African countries are left far behind in terms of people’s living standard.
A) CompareB) To compare C) ComparedD) Comparing
10) _______ how to deal with the trouble of the computer, Martin had to ask his brother for help.
A) Not knowB) Not knownC) Not to knowD) Not knowing