Spotting Errors

Use of the word 'with' is redundant. The phrase should be '....accidentally came across an old friend'.

The correct phrase should be 'to live in'. Some infinitive forms(live) take prepositions after them(in). E.g. She needs help to get up.

The correct phrase is 'defeated the French...'. "The" is used before French as we are referring to the army of France.

With although 'but' is not used. So correct phrase is 'Although you have made good to him, he still speaks ill of you.'

Correct phrase should be 'called on him' meaning 'to visit'.

Correct phrase should be 'the book' as sentence is referring to a particular book which is required for studying.

affection is always 'for'. So correct phrase should be 'even for'.

Correct use is .... an N. C. C. The pronunciation of 'N' in N.C.C starts with a vowel sound. Hence, 'an' will be used before N.C.C.

Each other refers to two, one another to more than two. As the first word of the sentence is 'all' ... we will use 'one another' instead of 'each other'.

Although there is lot of confusion regarding the capitalisation of 'Earth' as well as use of definite article 'the' before the name, we have to bear certain things in mind when we are dealing with grammatical usages. Earth is the name for one of the planets of the solar system. We use capital case when we name the other planets. So, unless we are talking of 'earth' as soil or the world, it is better to use it as a proper noun, in capital case, without article. 'Sun' is the central star of a planetary system. It is not used as a proper noun.

Correct word is 'into'....'into radioactive argon'. 'To' is indicative of incomplete action. But 'into' is more definite as it shows motion and change of form.

 Let us not confuse it with American English. For our purpose, 'practice' is a noun, 'practise' is a verb. We need a verb here. In part (a), bacteria is a plural noun; singular is bacterium, so 'are' should be used. Therefore, it is correct.

Beside means next to. Besides means apart from or and another thing. In the sentence we are talking about the physiological changes in young children apart from children of ages nine and fifteen. So correct word should be 'Besides'.

Correct sentence is 'when scientists say...'. While is used whenever we refer to simultaneous activity. Here, no other activity is referred to. In the sentence when scientists are saying about a few degrees increase, they are actually talking about a greater amount. So, 'when' will be used.

There is no condition of time, so 'till' will not be used. Secondly, negative implication is being stated in the sentence. Hence, 'until' will be used.