GE verbal questions and answers

GE is one of the top companies and it is the dream of many freshers like me to get a job there. I appeared for an interview at GE ast month. The test they conduct tries to judge your aptitude and based on the result in that test you move to the next round.
The test consists of quant, english etc.

The questions on English try to check your grasp on the language with the usage of preposition, articles, proper words, idioms, comprehension etc.

Some of the questions I remember are:

Fill in the blanks -
Renowned for maintaining his _____ even in the most volatile situations, David was utterly ________
1. dignity, incorrigible 2. composure, imperturbable 3. prosperity, blunt 4. equanimity, clairvoyant 5. control, insignificant

The --- waters of the shallow lake made the marine life clearly visible to the researchers.
1. turbulent 2. treacherous 3. serpentine 4. pellucid 5. putrid

Spot the error -
All of you will agree with me (1)/ that no problem faced by our (2)/ society is as grave and intractable (3)/ as this problem is. (4)/ No error(5)

We have done everything (1)/ that could be done(2)/ to avert the storm (3)/ which is now coming on (4)/ No Error (5)