Explanation

Go to Settings > Personalization > Lock screen, and select Screen saver settings.

In the Screen Saver Settings window, choose a screen saver from the drop-down list.

Explanation

In computing, an icon is a pictogram  displayed on a computer screen in order to help the user navigate a computer system.

Explanation

Nacl Chemical abbreviation for sodium chloride (table salt).

Explanation

Biceps is a muscle of the thigh located to the posterior, or back

Explanation

A complex sentence is a sentence that contains an independent clause with one or more subordinate clauses

Explanation

Keyboard is an input device.

Keyboard is similar to electric typewriter.

Keyboard uses serial port to connect with computer.

Keys on keyboard are of mainly three types:

Alphanumeric keys: letters and numbers 

Punctuation keys: comma, period, semicolon, etc.

Special keys: function keys, arrow keys, caps lock key, etc. 
Keyboard inventor: Christopher Latham 

Longest key on keyboard: Space key

Explanation

Explanation

"He promised that he will come" correctly matches the future tense with the verb “promised.”

It indicates a future action based on a past promise, which is standard in reported speech.

Explanation

اس سال کے تمام واقعات میں سب سے زیادہ اہم اور شاندار واقعہ “بیعۃ الرضوان” اور “صلح حدیبیہ” ہے۔ تاریخ اسلام میں اس واقعہ کی بڑی اہمیت ہے۔