Could you check my answer .. you which of the following sentences contains a linking verb?
a. yesterday, sarah experienced rock climbing for the first time. xxx
b. sarah seemed nervous at first. c. she climbed very well for a beginner. d. i think sarah wants to go again. you

changeable lenses of different focal lengths allows light to enter the camera,which then forms the image on light-sensitive film;

option c (nickel) is not found in earth's crust. the earth's crust basically contains eight (8) elements namely: oxygen, silicon, aluminum, iron, calcium, sodium, potassium and magnesium (listed in order of abundance).