（）in my life impressed me so deeply as my first visit to the Palace Museum.

单项选择题—Can you believe I had to pay 30 dollars for a haircut —You should try the barber's （）I go. It's only 15.

A. as
B. which
C. where
D. that

单项选择题People have always been（）about exactly how life on earth began.

A.curious
B.excited
C.anxious
D.careful

单项选择题We（）on this project for four hours. Let's have a rest.

A.are working
B.have been working
C.worked
D.had worked