相同质量的M、N两种活泼金属，分别与足量的稀盐酸在室温下发生反应（M、N在生成物中的化合价为均为+2价），生成H₂的质量m和反应时间t的关系如右下图所示。

⑴金属活动顺序是M比N         (填“强”或“弱”)；相对原的相对原子质量是M比N的         （填“大”或“小”）。

⑵M与稀盐酸反应结束后，消耗稀盐酸中溶质的质量为      g。

Nhu had two laptop computers for sale.Nhu wrote to Huong, offering one laptop computer for 6 million dong. Huong accepted the offer but after posting the acceptance changed her mind and sent another letter stating that she did not want the laptop. Both letters arrived at Nhu’s offi ce in the same delivery.Nhu despatched the laptop to Huong with an invoice for 6 million dong.Nhu wrote to Giang offering the second laptop computer for 6 million dong. Giang replied stating that he was only prepared to offer Nhu 5 million dong, which Nhu refused.Two weeks later, Giang contacted Nhu again, accepting Nhu’s original offer of 6 million dong. Nhu had already sold the computer to another person.Required:Explain whether Nhu has entered into legally binding contracts with Huong and Giang. (10 marks)