61. She ____the letter, put it in the envelope and handed it to her father.
A) folded B) wrapped C) rolled D) slided
62. In the last century, new drugs have ____ improved health throughout the world.A) inconsistently B) supposedly C) notedly D) markedly
63. Now a paper argues that organic chemicals in the rock come mostly from ____ on earth rather than bacteria on Mars.
A) configuration
B) constitution
C) condemnation
D) contamination