diff --git a/01_Day_JavaScript_Refresher/level1.js b/01_Day_JavaScript_Refresher/level1.js
index fcb49b9..71697ed 100644
--- a/01_Day_JavaScript_Refresher/level1.js
+++ b/01_Day_JavaScript_Refresher/level1.js
@@ -53,35 +53,74 @@ console.log(itCompanies[0], itCompanies[Math.floor(itCompanies.length / 2)], itC
 for(let i = 0; i < itCompanies.length; i++) console.log(itCompanies[i]);
 
 //   11. Change each company name to uppercase one by one and print them out
-for(let i = 0; i < itCompanies.length; i++) {
-    itCompanies[i] = itCompanies[i].toUpperCase()
-    console.log(itCompanies[i])
-};
-
+const companies = [...itCompanies]
+console.log(companies)
+// for(let i = 0; i < itCompanies.length; i++) {
+//     itCompanies[i] = itCompanies[i].toUpperCase()
+//     console.log(itCompanies[i])
+// };
 
 //   12. Print the array like as a sentence: Facebook, Google, Microsoft, Apple, IBM,Oracle and Amazon are big IT companies.
-
+let sentence = '';
+for(let i = 0; i < itCompanies.length; i++) {
+  if(i < itCompanies.length - 1) {
+    if(i == 5) {
+      sentence += `${itCompanies[i]} `
+      continue
+    }
+    sentence +=`${itCompanies[i]}, `
+  } else {
+    sentence += `and ${itCompanies[i]} are big IT companies.`
+  }
+}
+console.log(sentence)
 
 //   13. Check if a certain company exists in the itCompanies array. If it exist return the company else return a company is not found
-
+const has = comp => {
+  if(itCompanies.includes(comp)) {
+    let company = itCompanies.indexOf(comp)
+    console.log(itCompanies[company])
+    return itCompanies[company]
+  } else {
+    console.log(`${comp} is not found.`)
+  }
+}
+has('Facebook')
 
 //   14. Filter out companies which have more than one 'o' without the filter method
-
+const lessThan2O = []
+let count; let arr;
+itCompanies.forEach((company) => {
+  arr = company.split('')
+  count = 0
+  for(let i = 0; i < company.length; i++) {
+    if(company.charAt(i) == 'o') {
+      count++;
+    }
+  }
+  if(count < 2) lessThan2O.push(company);
+})
+
+console.log(lessThan2O)
 
 //   15. Sort the array using sort() method
-
+itCompanies.sort((a, b) => {
+  if(a < b) return -1
+  if(a > b) return 1
+})
+console.log(itCompanies)
 
 //   16. Reverse the array using reverse() method
-
+console.log(itCompanies.reverse())
 
 //   17. Slice out the first 3 companies from the array
-
+console.log(itCompanies.slice(0, 3))
 
 //   18. Slice out the last 3 companies from the array
-
+console.log(itCompanies.slice(itCompanies.length - 3, itCompanies.length))
 
 //   19. Slice out the middle IT company or companies from the array
-
+console.log(itCompanies.slice(Math.floor(itCompanies.length / 2), Math.ceil(itCompanies.length / 2)))
 
 //   20. Remove the first IT company from the array