Add spaces: Theseundesirableapplicationstendtomodifythesettingsofbrowsers;thus,youshouldnotbesurprisedifyounoticeIstsearch.comaddressinsteadofyourregularhomepage.

Answer: These undesirable applications tend to modify the settings of browsers; thus, you should not be surprised if you notice Istsearch.com address instead of your regular homepage.

Add spaces: AstoryaboutamiddleagedmannamedFúsi,whohasn’tfoundthecouragetoleavethenestandstepintotheadultworld.

Answer: A story about a middle aged man named Fúsi, who hasn’t found the courage to leave the nest and step into the adult world.

Add spaces: BecauseofthenumberandvarietyofinstrumentsmadeanddescribedbyTycho,previouscommentatorshaveassumedthathemadeinstrumentsforthesheersakeofkeepinghisinstrument-makersbusy.

Answer:
Because of the number and variety of instruments made and described by Tycho, previous commentators have assumed that he made instruments for the sheer sake of keeping his instrument-makers busy.