Complete with the past simple, present perfect or present perfect continuous form of the verbs. 请用动词的一般现在时、现在完成时或者完成进行时填空。 Jed: Have you ever (1 be) on a horse before? Bob: Well, I (2 be) on a camel, but I (3 not ride) a horse. Jed: Really? A camel? Bob: Yes. We (4 go) to Egypt a few years ago, and we (5 do) a camel trek into the desert. Jed: Wow! What (6 be) that like? Bob: Wonderful. We (7 sleep) under the stars. I (8 never see) anything so beautiful in all my life. What about you? Jed: Oh, I love horse-riding. I (9 do) it since I was ten years old. My grandfather (10 teach) me.