Which group of sentences best uses a variety of sentence patterns to convey meaning and the relationship between ideas? The cat curled itself into a ball. Its human scratched its chin. When it felt the scratching, it began to purr.

The cat curled itself up, so it was a ball. Its human scratched its ears, so it purred.

The cat curled itself into a ball. It began to purr when its human scratched its chin.

The cat curled itself into a ball. It purred. Its human scratched its chin.

A100 kmol/h stream that is 97 mole% carbon tetrachloride (ccl4) and 3% carbon disulfide (cs2) is to be recovered from the bottom of a distillation column. the feed to the column is 16 mole% cs2 and 84% ccl4, and 2% of the ccl4 entering the column is contained in the overhead stream leaving the top of the column. calculate the mass and mole fractions of ccl4 in the overhead stream, and determine the molar flow rates of ccl4 and cs2 in the overhead and feed streams. 12. mw_ccla- 153.82; mw_cs2-76.14.