Professor Backman took up scientific research for decades，and this is________he devoted all his life to.

  The work he devoted his time to _____ worth praising.

A. was    B. be

C. being  D. been

. The doctor was so kind that he devoted all his spare time he had _______the poor boy.

A. to helping    B. helped    C. helping     D to help

Before going abroad he devoted all he could _______ his oral English.

A. improve。mB. to improve

C. improvingD. to improving

In the 1880s, Mark Twain established and operated his own publishing firm. He also became interested in various investments, especially an elaborate typesetting machine. He lost almost $200,000 in investments in the machine between 1881 and 1894. Also, his publishing company declared bankruptcy (破产) in April 1894. Thus, in January 1895, Mark Twain found himself publicly shamed by his inability to pay his debts.

Mark Twain eventually recovered from his financial difficulties, through his continued writing and a successful lecture tour in 1895 and 1896. During this much-publicized tour, Twain lectured in such places as India, South Africa and Australia. By the time he returned, he had become an international hero. Twain enjoyed this attention, and his habits of smoking cigars or a pipe and wearing unconventional white suits contributed to his showy image. He also made use of his position as a public figure to criticize the US foreign policy.

Although he was recovering from his financial problems by 1898, Mark Twain had begun to experience tragedy in his personal life. Suzy, his oldest daughter, died of meningitis (脑膜炎) in 1896, while her parents and sister Clara were abroad. In 1903, Mark Twain sold the beloved house in Hartford, which had become too closely associated with Suzy’s death. His wife, Olivia, who had developed a heart condition, died on June 5, 1904. His youngest daughter, Jean, died on Dec. 24, 1909.

64. Which is not the reason why Mark Twain found himself in debt?

Because he devoted all his energy to his writings.

Because his publishing firm bankruptcy.

He lost almost $ 200 000 in investments in the machine between 1881 and 1894

Because he lost a large quantity of money in various investments.

65. How did Mark Twain pay off his debts?

A.  By borrowing money from the bank.

B.  By investing in foreign countries.

By writing articles and a successful lecture tour.

By printing his own articles and selling them for money.

66. It can be inferred that Mark Twain ________________.

hated smoking cigars

liked wearing black clothes

hated the US foreign policy at that time

hated giving lectures in the foreign countries