Why does the shark never stop moving？A．It never sleeps.B．It can only smell when moving.C．I

Never get off the bus（)it has stopped.A.ifB.as soon asC.untilD.or

Why do sharks normally swim between ten and twenty miles off the coast of Britain？A．They p

Why did the rice production decrease in the 1990s？A．Because African countries stopped deve

According to the passage, why are the chemicalsused in agriculture safe？A．They have never

According to the passage, why did some kids stop Sanz on the street？A．Because they wanted

Have you ever stopped to think why many people are complaining about all the pressu