4.My hands are dirty. I ______ the wall the whole morning but haven’t finished yet.
When first __________ to the market, the computer software was not a success due to its complexity in operation.
Unfortunately, the element Madam Curie devoted all her life her death .
Out of the crowded bus , who was dressed in a black suit and waved to a woman.
— I want someone to write the composition for me. — No. As a student, you ________ depend on yourself.
— He should have been warned of the danger. — ________, but he wouldn’t listen to me.