1 . I learned a lot about agriculture when ________ (pick) fruit on the farm. (所给词的适当形式填空)

4 . _______ an earthquake happens, the sensors can send electrical pulses to the control center and then ordinary people’s smartphones. (用适当的词填空)

5 . The Silk Road was one of the most important arteries (干线) of trade and culture in the world history. ______ planes and trains brought our world close together, it was the first link that ever connected the East and the West and the life blood of international trade in ancient time. (用适当的词填空)

6 . When_________( teach) English, whether to children or adults, you have to be very creative to keep their interest. (所给词的适当形式填空)

7 . ________ he asked the villagers on the banks of the river where he could find the legendary (传奇的) artist, they smiled and pointed down the river. (用适当的词填空)