Read the following passage and mark the letter A, B, C or D to indicate the correct word or phrase that best fits each of the numbered blanks from 26 to 30.

On 4 October 1957 the first satellite, Sputnik, was launched. Since then, thousands of spacecraft have been sent (26) ________ space. Every few weeks new satellites are put into orbit. Unfortunately, space is being (27) ________ by debris from these space flights. More than 70,000 objects have been left in space. Parts of rockets have been left. Old satellites have been abandoned. Other items, including a glove, a spanner and a camera, have been (28) ________ by astronauts. The situation up there is becoming dangerous. Both Russian and American spacecraft have been destroyed. (29) ________ astronaut would be killed if he or she was hit by a piece of rubbish. It would cost billions of dollars to collect all the debris, but if nothing is done the (30) ________ will only get worse. Sooner or later a satellite will be damaged by a large piece of rubbish and thousands more pieces of debris will be scattered.