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【单选题】
—Has Jack finished his homework yet? I am waiting for him. —I've no idea. But he _____ on it the whole afternoon. [ ]A.
is working
B.
works
C.
was working
D.
worked
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皮皮学刷刷变学霸
举一反三
【简答题】One day I was on a bus. I found an elderly woman ____1____ (stand) infront of me. She had a big bag __2___ her hand. "It's a virtue for a young person to help the old," I said to ____3___ (me). When I...
【单选题】克格莫的不稳定化合物(即被动自爆)威力无比。如果该化合物(混合物)是简单的无机物、能随时使用,且不是黑火药等,那么它最有可能是下列哪种:()
A.
X钾
B.
高氟酸
C.
氢气+氧气
D.
氢气+氟气
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