被动语态（注：这是留到“被动语态”那一讲用的,开学初不做）As oil is found deep in the ground its presence can not be determined by a study of the surface. Consequently, a geological survey of the underground rock structure must be carried out . If it is thought that the rocks in a certain area contain oil, a “drilling rig is assembled. The most obvious part of a drilling rig is called “ a derrick”. It is used to lift sections of pipe, which are lowered into the hole made by a drill. As the hole is being drilled, a steel pipe is pushed down to prevent the sides from falling in. If oil is struck , a cover is firmly fixed to the top of the pipe and the oil is allowed to escape through a series of valves. 1.2. A greeting card can warm a heart, hold a hand, lend a ear, pat a back, light up a face ,tickle a funny bone, dry an eye , surprise a child , woo a sweet heart, toast a bride , welcome a stranger, wave a good- bye, shout a bravo, blow a kiss, mend a quarrel, ease a pain, boast a morale, stop a worry and start a tradition.精美排版