write relative clauses without using the relative pronoun

i gave you a book. it had many pictures

the book..............................................................

i am reading a book at the moment. it is very interesting

the book..............................................................

i saw a bad accident ___________ iwas walking along the steeet yesterday.

A. before B. after C. as D, therefore

people should save energy ______________ the shortage of the natural resources

A because B because of C in spite of D despite

i knew many friends ___________ i had visited my grandparents in the countryside last summer

A while B after C when D as

they estimate that 1500 square kilometers of rainforests is cut every year

->

->

we knew that pencil lead is made from graphite, clay, water, and wax

->

->

they reported that the railway was buired under ton of rock and earth

->

->