A Write one word in each gap.SPACE PROBES BEHAVE STRANGELYIs an

A Write one word in each gap.

SPACE PROBES BEHAVE STRANGELY
Is an unknown force having an influence (1) Pioneer 10 and 11, NASAs oldest space probes? The probes have been travelling through space for over thirty years, but scientists have now (2).to the conclusion that their current position does not correspond (3)..predictions of where they should be. The probes appear to be (4).the control of something other than the suns gravity. Scientists are unsure of the cause (5).the probes slowness, but have narrowed (6)the possibilities to three main options. They (7).forward their suggestions at a conference this week. It is possible, but unlikely, (8) both probes are malfunctioning in the same way at the same time; our understanding of gravity may be wrong, or an unknown force in the universe is (9)a difference to the speed of the craft. Scientists say they will need to carry (10).more research before they can determine what the cause is.