While I was watching TV last night, a mouse ..........................across the floor.A. ran B. runs C. was running D. is running 5.Fish were among the earliest forms of life. Fish .........................on earth for ages and ages.A. existed B. exist C. have existed D. are existing6. The phone ..........constantly since Jack announced his candidacy for president this morning.A. has been ringing B. rang C. had rung D. had been ringing 7.In the last two decades, space exploration ...........great contribution to weather forecasting.A. is making B. has made C. made D. makes8.On July 20, 1969, Neil Armstrong .........down onto the moon, the first person ever to set foot on anotherbody.A. was stepping B. stepped C. has stepped D. was step9."When are you going to ask your boss for a raise?" – "....................to her twice already! I don’t thinkshe wants to give me one."A. I’ve talked B. I’ve been talking C. I was talking D. I’d talked10. "Paul, could you please turn off the stove? The potatoes ........................for at least thirty minutes."A. are boiling B. boiled C. have been boiling D. were boiling11. Jim, why don’t you take some time off? You ....................too hard lately.A. work B. worked C. were working D. have been