11- Thunder is caused by lightning, ------------ essentially a stream of electrons flowing
between or within clouds or between a cloud and the ground.
(گرامر، کنکور دکترا، ۱۳۹۸)

12- When ----------------- for the finest, freshest ingredients, always purchase organic
meats, vegetables, and condiments when possible.
(گرامر، کنکور دکترا، ۱۳۹۸)

13- Electric washing machines, ----------------- in 1925, significantly reduced the amount of
time spent washing a given amount of clothes.
(گرامر، کنکور دکترا، ۱۳۹۹)

14- They have little of the sullen, reticent disposition attributed to Indians generally, and
are cheerful, friendly, hospitable, -------------------.
(گرامر، کنکور دکترا، ۱۳۹۹)

15- The rate that bright comets enter the solar system implies there should be around
3000 of them buzzing around, ---------------- only 25 are known.
(گرامر، کنکور دکترا، ۱۴۰۰)

16- -------------- individual behavior is influenced by social networks is beyond dispute.

(گرامر، کنکور دکترا، ۱۴۰۰)

17- You can skip around within a section, so answer the questions that are easiest for you,
--------------- the more difficult questions for the end.
(گرامر، کنکور دکترا، ۱۴۰۱)

18- In the case of humans, when a person becomes infected and the resistant bacteria set
up home in the gut, the sufferer has two choices: ------------------
(گرامر، کنکور دکترا، ۱۴۰۱)

19- A lot of teachers are proposing ------------------ cell phones in classes because
they’re a distraction.
(گرامر، کنکور دکترا، ۱۴۰۱)

20- ----------------- it weren’t so cold and rainy, we could actually show you round the
place.
(گرامر، کنکور دکترا، ۱۴۰۱)