杠杆在生产、生活中有着广泛的应用,如图所示,下列工具中属于费力杠杆的是
①起子 ②镊子 ③筷子 ④羊角锤
A. ①②
B. ②③
C. ①③
D. ①④
答案:B
—What are you doing, Mike?
—I am _____ playing in the garden. I would rather _____ to play in such fine weather. [ ]
A. thought over, going
B. thinking about, to go
C. thinking of, go
下列属于天体的是
①陨星 ②恒星 ③正常运行的人造卫星 ④蟹状星云 ⑤哈雷慧星 ⑥狮子座流星雨 ⑦总星系
A.①④⑥⑦
B.④⑤⑥⑦
C.①②④⑤
D.②③④⑤