The old gentleman was a very ______ looking person, with grey hair and gold spectacles.
A. respectful
B. realistic
C. respective
D. respectable
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______ we have all the materials ready, we should begin the new task at once.
A. Since that
B. Since now
C. By now
D. Now that
If it ______ Professor Russel standing up for him, he would have had to leave.
A. hasn't been for
B. hadn't been for
C. was for
D. were for
Don't forget Ann wants a big doll, ______
A. do you
B. will you
C. don't you
D. won't you
化疗指数是指
A. LD5/ED50
B. ED95/LD5
C. LD50/ED50
D. ED50/LD50
E. LD1/ED99
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